Assessing the Performance of Current Strategic Policy Directions towards Unfolding the Potential of the Culture–Tourism Nexus in the Greek Territory

: In the UN Agenda 2030, tourism acquires a salient position as a critical sector, directly or indirectly inﬂuencing a number of Sustainable Development Goals (SDGs). The pursuit of Sustainable Tourism (ST) is founded on the respectful exploitation of the sector’s core ‘raw material’, i.e., the precious and vulnerable nexus of natural and cultural heritage, and a cooperative multi-actor endeavor of all those having a stake in this shared good. Strategic tourism policy decisions, formulated at the state level, frame actors’ actions, favoring a balance among economic, societal and environmental goals; and a transparent, concrete and supportive investment landscape, allowing the tourism sector to blossom. But how successful are these policy decisions in promoting a sustainable, resilient and durable tourism model by instigating the entrepreneurial community to invest in the vibrant culture–tourism complex? An effort to respond to this concern is made in this work, grounded in the ‘Culture–Tourism–Policy’ triptych and their interaction, the ‘policy cycle’ as a means of assessing policy performance towards establishing a sustainable/resilient ‘marriage’ of ‘Culture– Tourism’, and GIS-enabled spatial data management for an evidence-based assessment of policy outcomes. These three factors are closely intertwined in the assessment of strategic tourism policy decisions’ performance in a culturally vibrant and highly reputed destination, Greece.


Introduction
Chon and Olsen [1] have previously highlighted the increasingly competitive, complex and rapidly changing tourism market environment as well as the openness and fragility of the tourism sector to alterations of the external world. These attributes have placed national, state and local policy makers, as well as market stakeholders, in a continuous struggle to: grasp signals of potential future changes; and use this knowledge in order to make smarter decisions with regard to efficient and competitive ways for steadily adjusting to emerging challenges. Such a struggle implies the need to explore key drivers of change of the external decision environment as well as the opportunities and threats these raise; and utilize them as a means of proposing strategic options and framing policy decisions in the tourism sector that are adjustable to external signals.
Sustainability is deemed to be a major key driver that largely frames the future of the tourism sector nowadays [2][3][4][5][6][7][8]. Although sustainability, as a concept and an overarching goal to be achieved by developmental policies, has been at the forefront for more than three decades, the concept of sustainable tourism was not straightforwardly enunciated until almost the end of the second millennium [9,10]. Thus, no specific reference to sustainability with regard to the tourism sector was made in the Brundtland Report [11] or in the Agenda 21 [12]. However, the role of tourism as a key driver for development at the local/regional and national level that steers economic growth, balanced societal goals and environmental sustainability; and the necessity to properly integrate sustainability concerns into tourism policies, business practices and tourists' behavior are highlighted in the United Nations' Agenda 2030 for Sustainable Development, articulated through the 17 Sustainable Development Goals (SDGs). In this respect, the multi-level impacts of tourism on the natural and cultural environment are featured, e.g., overconsumption of natural resources, air pollution and noise, overproduction of solid waste and littering, deterioration of coastal and marine aquatic qualities and aesthetic degradation [6,13,14]; and the need to undertake policy action for the long-term flourishing of tourism destinations in sustainable and resilient manners is stressed [10].
Sustainability concerns of tourism destinations, in alignment with the United Nations' Agenda on Sustainable Development, lie today at the heart of current research endeavors [15,16]. Indeed, various researchers underline the need to establish a long-lasting relationship among the benefits of tourism in economic terms; the preservation of the precious and irreplaceable nexus of natural and cultural resources, which constitute the core 'raw material' upon which the value of this sector is built; and the societal concerns characterized by local lifestyles, value systems, beliefs and traditions of indigenous people. The role of the tourism sector in fulfilling the objectives in the aforementioned fields is acknowledged and is mainly featured in SDG 8 on 'inclusive and sustainable economic growth', SDG 12 on 'sustainable production and consumption' and SDG 14 on the 'sustainable use of oceans and marine resources' [17].
The fact that tourism is a highly climate-sensitive economic sector brings to the surface climate change (CC) as the second major key driver for its future development [18]. Although certain tourist destinations are more vulnerable than others, CC can potentially harm all different types, e.g., coastal, small islands or mountainous tourist destinations and the respective summer or winter tourism activities [6,14,17], thus altering the geography of tourism in a piercing and highly impacting manner. However, CC negative repercussions seem to be more pervasive in coastal and insular areas, thereby placing highly reputed destinations at risk, e.g., the Mediterranean [19,20]. Such ramifications can take the form of storms and extreme climatic events, coastal erosion, physical damage to infrastructures, sea level rise, flooding and water shortages, etc. [20,21]. The high vulnerability of coastal and insular regions also has to be taken into consideration in the light of tourism's severe seasonality. Intensive use of water resources in seasonal peaks, for example, coincides with low water regimes in dry periods, thus aggravating water management issues [7,21,22].
The above key drivers (sustainability and climate change) seem to have a decisive influence on the tourism sector since they unveil the imperative need for a certain transition to new, more sustainable and resilient future tourism development streams [23]. This transition, in turn, implies the abandonment of today's mass, overcrowded, spatially concentrated tourism patterns and the shift towards less crowded, milder, resilient, more evenly distributed and secure ones, also aligned also with the current health concerns, intensified by COVID-19. Benjamin et al. [24] also state that a resilient, equitable and more just sector that displays a respectful attitude to people and places and minimizes its impacts on the natural and cultural capital should emerge from such a transition. Having specified the attributes of this kind of transition in that manner, various researchers claim that these can be truly sustained by alternative tourism forms, e.g., eco-tourism [25], also taking into account the new challenges and lessons learnt from the COVID-19 pandemic and the severe impacts of this health crisis on the global tourism sector. OECD [23] converges towards this view by arguing that radical structural changes need to be put in action in the post-COVID-19 era; and a certain 're-booting' or re-branding of the tourism sector has to be accomplished by giving prominence to naturally and culturally endowed local and regional destinations.
Discussions on the topic bring cultural tourism to the forefront, i.e., the integration of the culture-nature nexus into the tourist products, or, stated differently, the establishment of the culture-tourism complex as a means to positively affect destinations' economies while minimizing the sector's environmental and social footprint [26]; and, as such, a powerful motive towards the preservation of the precious natural and cultural heritage [27,28]. Indeed, the contribution of the natural-cultural nexus to sustainable tourism development is broadly acknowledged nowadays [29]. In fact, in the era of extreme globalization and resulting cultural standardization, the trend towards more authentic, natural-and culturaloriented and aesthetic tourism experiences is further intensified and has rendered natural and cultural heritage the third key driver and a cornerstone for sustainable and resilient tourism development [30][31][32][33]. Pursuant to Kotler et al. [34], the macro-environment of a tourist destination is shaped by six fundamental identifiers, namely, social, economic, political, technological, natural and cultural identifiers. Despite all these elements are directly affecting the tourism sector, natural and cultural identifiers, e.g., landscapes, eco-sites, archaeological and historical sites and monuments, set the ground for a rich experiential tourist tapestry [6,[31][32][33][35][36][37]. Therefore, motivation for visiting a tourist destination is determined, inter alia, by the synergistic effects that arise owing to the presence of local natural and cultural assets and related products and services [38].
Given the above, the salient role attributed to the natural and cultural nexus in serving sustainability, resilience and inclusiveness may be immensely conducive to the attainment of a promising 'cultural turn' of the tourism sector [39]. The ultimate goal of this turn is twofold [40,41], namely, the incorporation of natural and cultural heritage as a quintessential part of planning and policy making so that the ground for durable heritageled developmental trails can be prepared; and the achievement of various instrumental benefits, such as economic benefits, benefits for the area per se and community and individual benefits.
The significance of sustainable patterns of tourism development to destinations is further reinforced by a fourth key driver associated with the prevailing trends in consumer preferences, i.e., the demand side. Contemporary tourists display maturity with regards to consumption. They are well travelled, sophisticated and, most importantly, environmentally aware and sensitive, experienced, educated and 'green-oriented' in their choices [6,42]. They demand quality and value and appreciate environmentally committed and resourcerespectful destinations, as well as authentic alternative tourism experiences. This brings to the forefront newly emerging destinations, characterized by their cultural and social identities and qualities, traditions, historical memories, local peculiarities, rural landscapes and natural land and seascapes, etc. [43,44]. New theme-based tourist products and services, broadly oriented towards one or a combination of three e-words: entertainment, excitement and education/experience of visitors [45], are gaining ground among consumers' preferences.
The strengthening of the tourism sector as a producer of economic and social value at a "glocal" (global/local) level and its contribution to the UN Agenda 2030 SDGs implies the urgent need to formulate and implement robust and coherent strategic policy directions capable of building a truly sustainable tourism model which reflects " . . . a quadruple bottom line of environmental, social, economic and climate responsiveness" [21] (p. 28); and firmly monitor their outcomes. Additionally, defining successful strategic policy directions in the era of the Fourth Industrial Revolution has at its core, inter alia, effective (spatial) large data management. This is deemed as essential input for managing available social, natural and cultural capital in a competitive, sustainable and innovative way and for adequately addressing market challenges by meeting demand preferences and framing them both with sustainability and resilience concerns. This brings to light the issue of cultural mapping as " . . . a process of collecting, recording, analyzing, and synthesizing information in order to describe cultural resources . . . " [46] (p. 2), a statement which entails the collection and interpretation of place-specific data, information and knowledge on natural and cultural assets. Cultural mapping has been recognized by UNESCO as an indispensable tool and technique for the preservation and promotion of tangible and intangible cultural heritage [47], thereby valuing its potential towards more informed policy decisions.
Bearing in mind the: (i) abovementioned decisive key drivers, i.e., sustainability, climate change, significance attached to the natural-cultural nexus and current trends in consumer preferences, that largely characterize the evolving decision environment and the contemporary challenges that need to be dealt with by the tourism sector; and (ii) the noticeable trend for a cultural turn in this sector, the present paper aims at exploring the extent to which tourism and the natural-cultural nexus, i.e., two elements traditionally perceived as strongly interwoven by many, are firmly interrelated in the Greek scenery as a result of an enabling policy framework.
In fact, Greece has been promoting the image of a 'summer myth' destination for decades, a challenging vision that is well established and has been at the epicenter of the country's tourism market campaigns. This prominent positioning in the global tourist destinations' map is widely based on its favorable mild climate conditions, the extended coastline and insular territories with pristine natural landscapes and seascapes, the exceptional cultural environment, the local traditions, the spirit of hospitality and the relaxing atmosphere these exude to visitors, etc. However, when taking into account the extraordinary natural and cultural capital of Greece and its broad distribution throughout the country's territory, it is apparent that this capital has not been adequately and sustainably exploited so far. As a result, tourism, i.e., the 'heavy industry' of the Greek state, despite being a fundamental pillar and a source of income for the national economy as a whole, as well as a source of employment and the main sustenance for local economies, especially in coastal areas, still remains a sector that stresses resources by means of applying significant societal, environmental and cultural pressures. Furthermore, it is obvious that a mass tourism model, characterized by extreme peaks during the summer season, fails to meet the goals of sustainable and resilient local development in the long run, while simultaneously exerting possibly damaging pressures upon the very resources upon which it is reliant.
Based on the above discussion, 'Tourism', 'Culture' and 'Policy' form the triptych of this work, cross-cut by spatial data management as a main supportive policy assessment tool ( Figure 1). This triptych falls under the rationale of the policy science and the 'policy cycle' approach in order for the successful interrelationship of its three constituents to be assessed. The research questions to be explored are formulated as follows:

•
How effective have the current strategic policy directions been so far in promoting the culture-tourism complex, i.e., sustainable and resilient, authentic, experience-based and culture-related alternative tourism forms in Greece? Or, stated differently, have these directions succeeded in confining the traditional spatially concentrated, mainly in coastal and insular regions, and mass-related '3S' (Sun-Sea-Sand) model, i.e., a resource-intensive and unsustainable one? Or has Greece taken steps towards altering the currently old-fashioned 'summer myth' narrative of the Greek tourism sector and motivating tourism entrepreneurship to invest in more sustainable and resilient projects that embrace the natural-cultural nexus? • Do entrepreneurial decisions fit with the distribution of the abundant natural and cultural heritage of the Greek territory? • How can technology-enabled spatial data management be used as a supportive policy tool for sustaining policy assessment and unveiling specific deficits in policy outcomes so that more informed or dedicated policy actions can be grasped?
In an effort to respond to these research questions, the paper is structured as follows: in Section 2, the methodological approach, which is founded on the rationale of the policy cycle context, is briefly described; in Section 3, the spatial distribution of natural and cultural resources and tourism entrepreneurship in the Greek territory, based on big data collection and GIS-enabled data management and mapping, is presented; Section 4 elaborates on the Greek strategic policy framework, which demarcates the spatial choices and developmental role of tourism, in alignment with the sustainable exploitation of the natural and cultural nexus; Section 5 proceeds with a qualitative and data-driven assessment of the effectiveness of the previous mentioned framework in successfully establishing the culture-tourism complex as the ground upon which the future flourishing of the tourism sector in Greece can be pursued; finally, Section 6 summarizes the obtained results and presents conclusions.

Methodological Approach
Policy decisions represent well-structured and data-driven choices to be implemented 'on the ground' [48]. As such, it is required that they are well informed or reflect societal concerns and priorities. The value of such policy decisions and their effective implementation is acknowledged as the means for shaping the way societies are evolving, reaching desired developmental goals and managing scarce resources in a sustainable and efficient way. Bearing this in mind, the steps of the methodological approach developed in this work are grounded in the rationale of the 'policy cycle' [49,50]. This cycle, as a sequence of distinct steps, frames the manner in which policy decisions are structured, formulated, evaluated, adopted, implemented, assessed and eventually re-oriented/re-designed. Furthermore, as stated by Listorti et al. [49], the following strongly interwoven features are listed among the most salient ones of such a policy cycle:

•
Evidence-based policy making, implying a sound and robust set of data, necessary for illuminating policy inefficiencies and orienting policy directions; and • Integrated approach, which entails following the distinct steps of the policy cycle, each of which serves particular purposes and can draw upon knowledge, tools and approaches that emanate from a range of disciplines.
The structure of a policy cycle is not rigid, but can be adjusted to the various policy formulation, evaluation and assessment contexts. In this work, such an adjustment is carried out in order to better reflect the policy research question and the steps/content used for handling it. Regarding the research question, the emphasis of the implementation of the policy cycle approach is not placed on the formulation of a certain policy (see Step 3 in Figure 2). Conversely, it is placed on the assessment of policy outcomes of an already enforced policy, which targets, among others, the promotion of the culture-tourism complex in the Greek state (Step 4 in Figure 2). More specifically, the adopted methodological approach aims at assessing the efficacy of the Greek strategic policy framework for tourism development regarding its contribution to the promotion of an even spatial distribution of tourism activity or the determination of intervention areas whose resources are being exploited beyond capacity and, especially, the establishment of the culture-tourism nexus. Therefore, the way tourism entrepreneurship embraces the abundant and spatially dispersed natural and cultural resources so as to facilitate the emergence of more sustainable and resilient cultural tourism products is explored. The use of contemporary technological advancements, with a particular focus on Geographic Information Systems (GIS)-enabled methods, techniques and tools for managing large datasets, lies at the heart of such an assessment. The steps of the proposed methodological approach are ( Figure 2):

•
Step 1: 'Setting the Scene'. In this step, the key drivers of the external environment that can frame policy decisions regarding a problem at hand are identified. Concurrently, global key goals, such as sustainability and resilience, which are deemed to be overarching or 'umbrella' goals in each planning and policy exercise, affecting policy formulation with regard to each individual field, are considered. Based on the scope of this work, climate change as well as tourism demand trends are also perceived as important key drivers framing the decision environment. The aforementioned key drivers are already identified and briefly discussed in the introductory section of this work.

•
Step 2: 'Delving into the Policy Problem/Context'. This step elaborates on the problem addressed by a policy exercise and the relevant spatial context (e.g., local, regional, national or supranational). It implies a deep understanding of the specific attributes of both the problem at hand and its spatial context so as to ground the policy exercise in field-related evidence [49]. In the particular policy exercise of the present research, the type and spatial distribution of cultural and natural resources as well as entrepreneurship developed on the basis of these resources are perceived as the key elements of this step. Thus, using a national spatial reference, a data-driven thorough insight into the type and spatial distribution of both cultural and natural resources as well as tourism entrepreneurship is carried out, framing the processes/work of the subsequent steps.

•
Step 3: 'Defining Policy-Goals, Objectives and Targets'. Based on the previous steps, this step is associated with the articulation of a relevant policy for problem solving as well as the goals, objectives and targets to be reached by its implementation. Work undertaken in this step is characterized by the problem at hand and the specific spatial context (output of Step 2), while it also takes into consideration the key drivers and overarching policy goals of the external environment (output of Step 1). In the context of this step, alternative policy options are structured and evaluated (e.g., alternative scenarios and policy paths for their implementation) so as to end up with the most effective one, precisely formulate it and implement it. For the purpose of this work, however, it should be noted that the current policy framework and its goals, objectives and targets, mainly characterized by its financial (provision of incentives in support of tourism entrepreneurship) and spatial dimension (Special Framework for Spatial Planning for Tourism), are taken for granted; while it is precisely its effectiveness that is subjected to investigation and analysis in the subsequent steps. Therefore, the paper attempts to clarify the current policy directions and their specific goals, objectives and targets as these unfold in relative policy framework at this stage.

•
Step 4: 'Assessing Policy Outcomes and Targets' Achievement'. This refers to a critical step of the policy cycle, which aims at assessing a certain policy's performance regarding predefined end states. Identification of divergences or gaps between predefined policy goals, objectives and targets on the one hand and those actually achieved by policy implementation on the other, coupled with interpretation of these gaps, can provide the necessary input for Step 5 for the management of policy failures by a properly informed adjustment or reorientation of the policy decisions. This stage forms the core of this work as a means to identify gaps and thus steer more knowledgeable policy remediation towards desired outcomes. The key question is whether and to what extent tourism entrepreneurship goes hand in hand with natural and cultural assets, or, stated differently, how effective the Greek developmental and spatial policies are for promoting a successful 'marriage' of culture-tourism. The response to this question displays the capabilities of technological tools for managing the sizeable data sets produced in Step 2 of the present study. The vital role of such tools is highlighted as highly supportive data management and analysis frameworks in the policy cycle context for policy formulation, evaluation, assessment and monitoring. In the present work, these tools possess a decisive role in the work carried out in Steps 2 and 4 (see Figure 2). • Step 5: 'Monitoring/Adjusting/Reorienting Policy'. This step rests upon the continuous monitoring of the outcomes produced by a certain policy and the remediation of the previously identified gaps (Step 4) or gaps emerging from potential developments in the external environment that may have adverse effects on the policy issue at hand. When such outcomes are observed, the final process pertaining to this step is to raise a call to action (e.g., the pandemic crisis' impact on policy and the need for readjustment of previous goals). Tracking such irregularities can trigger and inform remediation action by means of adjusting, reorienting or calibrating policy decisions.

Delineating the Spatial Context: Mapping the Distribution of Natural and Cultural Resources and Related Tourism Entrepreneurship in Greece
In this section, an effort to explore and delineate the spatial context/distribution of the core pillars of this work is carried out, namely, 'culture', through the study of the type and spatial distribution of tangible natural and cultural assets; and 'tourism', via delving into the type and spatial distribution of tourism entrepreneurship (see Step 2 of Figure 2). This task is accomplished by the collection, analysis and visualization of data pertinent to the spatial pattern of Greece's salient and tangible natural and cultural reserves on the one hand and the related tourism entrepreneurship on the other. The NUTS2 level is used as a spatial reference for this endeavor. In this respect, data were collected, recorded, processed and visualized for every Greek region, apart from the Attica Region and the Regional Unit of Thessaloniki. Owing to the wide dissimilarity between these two areas (metropolitan, population centers, high density and volume of relevant uses, landmarks of global appeal) and the rest of Greece, it was deemed that an analysis similar in scope would be required to contain increasingly granular information, as well as different approaches with regards to data analysis.

Data Sources and Limitations
Multiple open data sources were utilized in the context of this work, such as Open Street Map (OSM), the Hellenic Statistical Authority, the Greek portal for open geospatial data and services (Geodata.gov.gr) and the Greek Open Data Hub.
However, a series of difficulties were identified during the data collection process. The most significant one relates to the fact that various publishers release spatial data that, often, have different structures. More specifically, data are collected on the basis of different methodologies and are available in different formats, thereby potentially undermining the accuracy and internal consistency of the final outcome. For example, OSM uses the World Geodetic System 1984 (WGS84-EPSG:4326) as the reference coordinate system for the provided data, whereas Greek governmental agencies use the Greek Geodetic Reference System 1987 (GGRS87-EPSG:2100). Additionally, the provision of geographically incomplete spatial data and information by the Greek authorities is a usual phenomenon. More specifically, an absolute lack of open spatial data on traditional settlements or entrepreneurial activities is observed. In this case, highly detailed (business name, location, type of business) OSM data were used. Bearing in mind that OSM releases Volunteered Geographic Information (VGI), i.e., a particular form of crowdsourcing that refers to the volunteered production and provision of geographic information by individuals [51], as well as the fact that crowdsourcing is not popular with the Greek public, data received from OSM are considered to be indicative of the spatial distribution of the relevant data categories and not an absolute reflection of reality. Nonetheless, it should be noted that OSM data are also sourced from well-known contributors who have vested interests in data integrity and validity, including commercial users such as Amazon, Facebook and Foursquare, as well as state actors. Users of this kind facilitate data collection and aggregation, supporting OSM's breadth of scope and accuracy.
Another important implication is associated with the quality and the temporal dimension of data collection (methods and time frequency of data collection/updating). The Greek authorities follow scientifically sound methodologies and apply advanced methods and procedures for gathering, correcting and validating spatial data, while the time gap between data updates is quite broad. Conversely, OSM data, as crowdsourced data, might contain errors (mostly gross errors); however, considering the extended user base and the service's extremely user-friendly interface, they are usually updated on a daily basis.

Mapping Natural and Cultural Resources at the Regional (NUTS 2) Level
The Greek territories are endowed with a remarkable wealth of natural and cultural resources that provide them with a unique, multidimensional identity. For the purpose of the present work, a plethora of data concerning the type and spatial distribution of natural and cultural resources at the regional level were collected from various sources. Data and information on the location and properties of tangible natural and cultural resources (natural and cultural monuments, churches, castles, archaeological sites, museums, cultural infrastructures, traditional settlements, national parks, canyons, lakes and rivers, NATURA 2000 areas, etc.) were collected, recorded, processed and visualized in order to produce natural and cultural maps for every Greek Region, apart from the Attica Region and the Regional Unit of Thessaloniki.
According to the generated maps (Figures 3 and 4), which depict the natural and cultural resource availability and spatial dispersion for every administrative region, the following remarks are made: • A large portion of the Region of the North Aegean, an insular region that comprises the islands of the northeastern Aegean Sea, is occupied by evenly distributed protected areas of great ecological importance, while numerous wildlife refuges, NATURA 2000 areas and thermal resources are detected. These natural resources can become the 'vehicle' for the development of nature-based and spa tourism, as well as health and wellness tourism. The Region of the North Aegean is also characterized by a complex mosaic of culture and civilization, composed of UNESCO World Heritage sites, traditional settlements, industrial heritage sites, archaeological sites and medieval and ancient castles. • A great part of the Region of the South Aegean, an insular region that consists of the Cyclades and Dodecanese Island complexes located in the central and southeastern Aegean Sea, is covered with protected areas of major environmental significance and exhibits a relatively uniform distribution pattern. Moreover, plenty of wildlife refuges, as well as thermal resources, can be found here. As in the case of the North Aegean, the Region of the South Aegean has the potential to develop alternative experiencebased tourism forms, founded on the promotion of nature, health and wellness. As far as cultural capital is concerned, this region possesses traditional settlements, industrial heritage and archeological sites, catholic cathedrals and fully preserved medieval castles.

•
The Region of Crete, an insular region that includes the island of Crete and numerous neighboring islands and islets, has a significant stock of natural and cultural resources composed of protected areas, evenly distributed wildlife refuges, rivers suitable for sports and physical activities, traditional settlements, archeological sites, UNESCO World Heritage sites and museums of various types. • A considerable part of the Region of Peloponnese, a mainland region located in southern Greece, and the Region of Central Greece, a mainland region that covers the eastern half of Central Greece, including the island of Euboea, are occupied by protected areas and wildlife refuges, with both being evenly dispersed, while thermal resources and several rivers suitable for sports and physical activities are also found here. These resources can contribute to the development of nature-based tourism. Furthermore, this region has a great variety of archaeological sites, museums of various types and a significant network of scattered traditional settlements.

•
The Regions of Western Greece, located in the western part of mainland Greece; Thessaly, a mainland region in Central Greece; Western Macedonia, situated in northwestern Greece; Central Macedonia, covering the central part of northern Greece; and Epirus, located in the northwest part of mainland Greece, have the opportunity to develop nature-based health, wellness and sports tourism since a significant part of them is covered with protected areas of particular ecological importance, evenly distributed wildlife refuges and national parks, while thermal resources, rivers and lakes are also detected. These regions also possess archaeological sites, UNESCO World Heritage sites (in the Region of Western Greece), museums of various types, religious monuments, ancient and medieval castles and several traditional settlements.

•
The Region of Eastern Macedonia and Thrace, situated in the northeastern part of the country, has opportunity to develop nature-based health and wellness as well as sports tourism activities since it is characterized by an extremely wealthy natural environment, composed of evenly distributed protected areas, wildlife refuges, thermal resources and several rivers. Furthermore, it possesses numerous traditional settlements, archaeological and historical sites, castles, museums and religious monuments.
Owing to the location and the historical evolution of this region, special temples and places of worship, such as mosques and other various types of Islamic monuments, can be found.

•
The Region of the Ionian Islands includes all the Ionian Islands, apart from the island of Kythera, and has extended protected areas of great ecological importance as well as several wildlife refuges evenly distributed across the regional units. These resources can decisively contribute to the development of nature-based tourism. Regarding its cultural profile, this region has several traditional settlements, religious monuments, archaeological sites and museums of various types.

Mapping Tourism Entrepreneurship at the Regional (NUTS 2) Level
The focal point of the Regional Innovation Strategy for Smart Specialization, RIS3, (see Section 4 below), which reflects the adaptation of the Greek legislative framework to the European policy directions on spatial specialization, is the establishment of large-scale entrepreneurial networks at the regional level, which are expected to substantially support business clusters and foster the extroversion of the pertinent business complexes. Moreover, an extensive literature review highlights the significance of spatial proximity [53,54] to the genesis and progress of such clusters. This holds true especially for the tourism industry by virtue of the nature of the tourist product per se. Tourism consumption takes place at the local level. The final product is a result of successful collaboration among multiple businesses, and tourism activities flourish in the vicinity of areas that are highly marked by the presence of natural and cultural resources. Of course, there are plenty of factors that play a central role in clusters' creation and development, with the most important ones being the relevance of production, the range of supply networks, digital readiness of the business environment and the potential for building true and solid cooperative relationships.
Taking the above into consideration, this particular subsection describes the process of analyzing the spatial distribution of tourism entrepreneurial activities for each administrative region. Since the Greek state does not provide the public with such types of spatial data and information, volunteered OSM data were used for this purpose. OSM data in the context of the present research, can be perceived as a rough indication or a proxy of business distribution, which can lead to solid statistical conclusions on the spatial development and organization of tourism-based entrepreneurship in the different regions.
Data and information pertinent to various tourism-based entrepreneurial activities (e.g., hotels, motels, hostels, guest houses, car and bicycle rentals, gift shops, tourist operators and offices, thematic parks, kiosks, chalets, zoos, malls, organized campsites) were gathered, processed and visualized so as to generate the respective maps for every Greek region (excluding the Attica Region and the Regional Unit of Thessaloniki) and finally produce a heat map that covers all of the country ( Figure 5). Figure 5. Visualization of the spatial density of tourism-related entrepreneurship for every Greek region (apart from the Attica Region and the Regional Unit of Thessaloniki) [52].
From a GIS perspective, heat maps are deemed to be one of the most useful and efficient visualization tools used for the depiction of the geographic clustering of dense point data. It is an interpolation technique used for the determination of the density of geographic entities [55]. As Dempsey [55] claims, "Heat mapping is a way of geographically visualizing locations so that patterns of higher than average occurrence of things likes crime activity, traffic accidents, or store locations can emerge". In practice, heat maps present the areas in which intense concentrations of point data are observed to be the ones that display increased concentrations of relevant data points and can directly give valid answers to questions regarding the distribution of these data. As such, they offer a significant visual aid, but by no means can they be perceived as an accurate way of representing point density.
Pursuant to the cartographic analysis of tourism entrepreneurship's spatial distribution for every Greek region, as well as the results presented in Figure 5, the following remarks are made:

•
Tourism-based entrepreneurial activities are mainly concentrated in the coastal (Nafplio, Patras, Volos, Chalkidiki, etc.) and insular parts of the country (Crete, Ionian Islands, Rhodes, Cyclades, etc.). This is due to the long-lasting national developmental and tourism policy, which has been promoting, almost exclusively, the 'Sun-Sea-Sand' model, thus favoring the explosive blossoming of mass tourism in the coastal and insular areas. As a result, such places have been drastically boosted for decades, a fact that has unavoidably led to severe regional disparities between the coastal/insular areas and the hinterland, with the latter remaining in the shadows, since its natural and cultural potential has been totally marginalized by the dominant tourism trends. • Figure 5 makes apparent the fact that the coastal parts of both the insular areas and the mainland form a continuous tourism-oriented entrepreneurial front, a U-shaped form that extends from the northern borders of the Ionian Islands Region to the coastal areas of the Region of Western Greece and the Peloponnese (to the south), while it proceeds to the Region of Crete and then moves again up to the north, towards the Regions of the South and North Aegean.

•
The spatial structure of tourism-related businesses, located in the hinterland, reveals a twofold inequality. On the one hand, tourism entrepreneurship appears to significantly lag behind, contrary to the coastal and insular areas, as they exhibit substantially lower density. On the other hand, imbalances emerge within these mainland regions, since tourism business activity exhibits higher density around urban centers and a low or medium degree of diffusion as the distance from the urban fabric starts to increase. In addition, there are many Greek locales in which tourism-based businesses are literally non-existent.

Current Policy Frameworks for Tourism Development in Greece: A Succinct Review
Having already explored two out of the three pillars of this work (see Figure 1), namely, 'tourism' and 'culture', and also having elaborated on their spatial distribution across the Greek territory, this section focuses on the third pillar, namely, 'policy' in relation to tourism and culture (Step 3 of the methodological approach of Figure 2). Towards this end, nationwide strategic policy guidelines that currently frame the development of the Greek tourism sector and also touch upon the aspects of natural and cultural assets, are analyzed. Specific emphasis is placed on the goals/objectives/targets these set and the tourism pattern they attempt to attain, as well as the way they promote the relationship between tourism and the cultural-natural nexus to reach more sustainable and resilient tourism pathways. Such information, coupled with the outcomes of data processing on natural/cultural resources and tourism entrepreneurship (Step 2 of the methodological approach of Figure 2), form the basis on which to carry out the work included in the next step of the policy cycle approach (Step 4 of Figure 2), where a qualitative and spatial datadriven assessment of the effectiveness of strategic policy directions towards facilitating the establishment of the culture-tourism complex is undertaken.
The Greek strategy for spatial organization and the overall exploitation of the developmental potential of the tourism sector is articulated through the respective national institutional framework ( Figure 6). This defines all the necessary spatial development criteria, restrictions, incentives and other qualitative parameters for building up a thriving tourism sector that can act as a pillar for the national economy in the medium and long run. The scope of this framework is to achieve and secure the sector's growth in conjunction with the sustainable and resilient management of natural and cultural resources, the key drivers for tourism development. Its various constituents are presented in the following subsections.

General Framework for Spatial Planning and Sustainable Development
The General Framework for Spatial Planning and Sustainable Development (GFSPSD) was adopted in 2008 and constitutes the most fundamental policy text regarding Greece's spatial development strategy. It actually reflects the country's strategic choices as to its spatial organization and development. In other words, GFSPSD is a national, strategic, multi-sectoral, territorial plan that provides all the general guidelines pertinent to the organization, management and development of the Greek territory [56]. These guidelines stem from or are framed by European and international (spatial) policies and are incorporated into the Greek legislative framework. The GFSPSD is structured on the basis of [52] the long-term monitoring and assessment of developments that occur in the broader (external) decision environment as well as the benefits that emanate from these developments, with respect to the national space and relevant resources.
Focusing on the tourism sector per se, the GFSPSD refers, inter alia, to the expected increase in tourist flows, the need for a dynamic and extroverted tourism sector, the opening of the Greek tourist market to new markets (e.g., Asian travelers) and the necessity to substantially upgrade international transport networks, an essential factor that can drastically determine the sector's growth at the national level [57]. The GFSPSD also recognizes that the developmental perspectives of the 'Sun-Sea-Sand' tourism model, promoted thus far, are completely saturated due to [57]: (i) the entry of other Mediterranean countries into the tourist market, thereby expanding visitors' choices and strongly intensifying competition; (ii) the mounting international trend for promoting personalized, authentic and experiencebased tourist products [58][59][60], which are in contrast with the highly distinguished Greek mass tourism models; and (iii) the gradual degradation of available resources owing to over-exploitation, which often exceeds their carrying capacity.
Furthermore, GFSPSD stresses the unique cultural wealth of the country, as well as its natural and cultural comparative advantages, both in the mainland and the insular parts. However, these resources, natural and cultural, are not fully exploited due to regional geographic peculiarities that provoke critical and acute accessibility issues, the lack of critical mass that entails relatively high costs of providing and maintaining services and infrastructures and, in certain cases, the developmental model adopted per se, which induces alterations to the natural, cultural and social environment with consequent adverse effects on the natural and cultural resources upon which the tourist product is founded [57].

Special Framework for Spatial Planning and Sustainable Development for Tourism
In 2009, Greece embedded the Special Framework for Spatial Planning and Sustainable Development (SFSPSD) for Tourism in its legislation, which endeavors to adopt a scientifically sound, integrated spatial planning and set it as a fundamental prerequisite for the rational development of tourism activities nationwide. Its ultimate goal relates to the promotion of sustainable tourism development through the establishment of synergies among sectoral policies, conflict resolution with other activities and diversification of the tourist product.
More particularly, the SFSPSD for Tourism is a sectoral territorial plan, effective nationwide, that provides specified guidelines (general guidance stems from the GFSPSD), rules and criteria for the spatial structure, organization and development of the tourism sector. These guidelines aim at categorizing the Greek territories by type, founded on the degree of tourism maturity they exhibit, their geomorphology and the sensitivity of their natural and cultural capital. Thus, Greek territories are classified into developed tourist areas, developing tourist areas, lagging-behind areas of tourist interest and predominant uses others than tourism, coastal areas and islands, mountainous areas, etc. The guidelines also refer to the spatial organization of special forms of tourism, which are based primarily on the comparative advantages that are attributed to the local natural and cultural wealth, and have the potential to thrive in various regions and claim a niche in special interest tourism markets. Therefore, alternative tourism forms that can blossom in the Greek territories are cultural tourism, nature-based tourism, sea tourism, religious tourism, spa and therapeutic tourism, diving tourism, sports tourism, conference tourism and urban tourism, etc. [61].
The SFSPSD for Tourism alleges that the international tourism market has not yet fully exhausted its growth potential, which is expected to expand even further in years to come. This is deemed to be a critical factor of the broader environment and should be taken into serious consideration when crafting the national tourism strategy. Moreover, the SFSPSD for Tourism places particular emphasis on the country's rich natural and cultural reserves, around which significant tourism activities can flourish. These activities ought to be spatially balanced, sustainable and resilient and should also underpin complementary relationships and synergies, harmoniously integrated into the local value systems [6,32,33,51,52]. However, such goal setting must be strategically articulated in a way that ensures fulfillment of the overarching goals of today's reality, i.e., sustainability, resilience, conservation and promotion of natural and cultural resources, as well as adaptation to climate change impacts.
The SFSPSD for Tourism seems to be moving in a positive direction as regards the solidification of a more sustainable and resilient tourism scheme, since it seeks to diversify the Greek tourist product by promoting the unique local identity of every region through the development of alternative, high-quality, authentic and experience-based tourist products and by shifting towards special tourism market niches. This may be drastically conducive to the broadening of the country's potential to augment its share in the global tourism market while placing less emphasis, at the same time, on the mass tourism destination 'label' that has been haunting Greece for several decades. Its fundamental purposes focus on [62] promoting balanced development while simultaneously showing great respect to the integrity of natural and cultural resources; steering a fairer and more just distribution of blended value creation, offered by the various sectors, in support of less-favored and lagging-behind regions; boosting employment and income; improving cooperation and increasing the average size of enterprises; advancing technology adoption and encouraging businesses' adjustment to the information and communication era; shaping a new extroverted national identity (branding); improving competitiveness in sectors that are mainly characterized by high added value and knowledge intensity; moving up the value chain so as to achieve the production of more complex products; preserving and saving natural resources in favor of circular economy models; providing better services; attracting foreign direct investments; and ultimately securing a better position in the international division of labor for the country.
Finally, with reference to the Greek tourism industry, the new development law for investment incentives stipulates the following regulations/interventions [62]: • Establishment or expansion of three-star (or higher) hotels.

•
Modernization of integrated hotels that are classified as at least three-star hotels or are upgraded to that category (or higher).

•
Expansion and modernization of integrated hotels that have ceased their operation. • Establishment, expansion and modernization of three-star (or higher) integrated organized tourist campsites. • Establishment and modernization of integrated hotels that occupy traditional or preservable buildings and belong or are upgraded to the two-star category at least.

•
Founding of complex tourist accommodation facilities. • Establishment of special interest tourism infrastructures (conference centers, golf courses, tourist ports, ski resorts, theme parks, thermal tourism facilities, etc.).

•
Submission of investment plans for the creation of agro-tourism and wine tourism facilities by organized business clusters. • Establishment of youth hostels.

Research and Innovation Strategy for Smart Specialization (RIS3)
In an effort to harmonize with the radical technological advancements and embrace European Union's (EU) guidelines on how to properly exploit the comparative advantages of every region (NUTS 2 level), Greece has prepared a series of reports on the Research and Innovation Strategy for Smart Specialization, RIS3, in order to renew the national and regional planning scheme. At the national level, RIS3 mainly aims at further enriching or specializing national and sectoral policy choices, articulated in respective national/sectoral strategic spatial plans, as well as in Operational Regional Programs and Regional Spatial Plans. RIS3 is a comprehensive agenda for economic transformation, adapted to the specifics of each spatial entity of the administrative system that includes eight priority sectors, namely, [63] agro-food; Information and Communication Technologies (ICTs); environment and sustainable development; energy; health and pharmaceuticals; materials and constructions; transport and logistics; and culture, tourism and Creative Industries (CI).
As far as the tourism industry is concerned, the main goal of RIS3 is, inter alia, the recognition of the 'culture-tourism' nexus as a key driving force for the development of internationally competitive, authentic and experience-driven products and services in the fields of culture and tourism, based on the adoption and use of new, cutting-edge technologies [64]. Moreover, the creation/establishment of business clusters, i.e., geographic concentrations of interconnected enterprises and institutions in a particular domain [65] that can be conducive to the local economic growth is considered to be a critical element for the implementation of RIS3.

Assessing Entrepreneurial Exploitation of Natural and Cultural Capital: Critical Remarks
In this section, the effectiveness and success of the Greek policy frameworks that target specific goals and objectives regarding the tourism sector and seek the sustainable exploitation of natural and cultural resources for tourism-related purposes are assessed (Step 4 of the policy cycle of Figure 2). The ultimate goal is to explore the level of connection/interrelationship between the natural and cultural resources on the one hand and tourism-oriented entrepreneurial activities on the other. Policy assessments can be of quantitative and/or qualitative nature and follow a two-step approach, namely:

•
The first step, which aims at exploring disharmonies among the distinct constituents of the national policy framework (Section 4) that restrain the consolidation of the culture-tourism complex, i.e., the intertwining of cultural assets with tourism; and • The second step , which addresses the spatial counterpart of these disharmonies, i.e., the gap between the spatial pattern of natural/cultural capital and that of tourism entrepreneurship, as discussed in Section 3.
Critical consideration of both will bring to the surface potential inefficiencies and distance from predefined goals, thus allowing dedicated policy remediation actions to be undertaken.

Assessing Coherence of Strategic Policy Frameworks: Key Findings and Critical Remarks
Pursuant to the delineation of the aforementioned policy frameworks, although these share a common goal setting, they nonetheless place the Greek tourism industry on different 'road maps'. The SFSPD for Tourism targets balanced tourism development in a manner that ensures the widest possible and most efficacious exploitation of available resources. On the other hand, RIS3 encourages market-based solutions by promoting the growth of already established tourist destinations and introduces the efficiency of local markets as an assessment criterion for the allocation of aid/funding to these destinations. Despite this discrepancy being seemingly marginal, when considering its impact on future endeavors for planning a balanced development of tourism activities, in the long run, it may lead to radically different tourism landscapes, both in qualitative and quantitative terms, in the country's various areas.
However, it should be noted that in case of lagging-behind (in terms of tourism maturity) Greek Regions, these rely on a completely different economic structure founded on productive sectors other than tourism. Thus, the development of tourism activities may not be supportive or complementary to the already established ones; on the contrary, they might undermine and prevent them. For example, a local economy based on industrial production is more tolerant of activities that might provoke environmental nuisances; therefore, the imposition of strict ecological regulations, which is mandatory for tourism development, may impede industrial development and hence induce risks relevant to a radical shift in the local development models. Additionally, mature tourist destinations, have the appropriate know-how, such as highly specialized human capital (from customer service in restaurants to multilingual tour guides and administrative employees), and experienced stakeholders that are well adapted to local conditions. Thus, the transfer of intangible know-how is a much more complex process in comparison to other activities, but also very limited in terms of implementation potential.
The abovementioned disharmonies are also evident in the new Development Law for investment incentives (L. 4399/2016), which promotes tourism infrastructures that fall into the three-star category or higher. Although such goals may be considered satisfactory with regards to balancing tourism development, at the same time they completely defy the development cycle of an area that possesses lower quality infrastructure, but wishes to upgrade it. Therefore, space is perceived as a 'whiteboard' that is called to make progress in a balanced way, but commencing from a common starting point, a hypothesis that can be readily dismissed. However, even if this assumption were right, the ongoing capital demand for maintaining a given quality standard in areas characterized by different degrees of tourism development is strongly differentiated. This is justified by the fact that the quality of accommodation is only one pillar of tourism development. For example, a mature tourist destination has the advantage of an extended supplier network of relevant goods and services, whereas non-developed areas in the field of tourism have very little chance of creating or gaining access to networks of this kind in a reasonable timeframe. This could in reality impede locales that exhibit low or limited tourism development from growing in an organic, sustainable manner.
The above risk could have been avoided if central policies were focused on promoting tourism development horizontally, with the participation of local actors in co-decision processes, rather than adopting action plans of a vertical character, as in the case of RIS3. Such an approach is necessary to achieve the goal of bottom-up developmental planning and guarantees that local communities are responsible for formulating strategic choices regarding their area's economic development. Concurrently, it is ensured that policy results are regularly monitored and assessed using carefully selected criteria based on local experience and tacit understanding of each location. Thus, proposed policy directions are reviewed and amended according to the empirical knowledge of local communities, but also in alignment with the commitments and strategic choices that emerge from supra-local authorities' recommendations.
Policies exclusively oriented towards tourism should not be deemed a panacea since they are rarely fruitful for all sectors. Natural resources and artificial infrastructures become saturated, water and energy demand increases, and business activity often grows to the detriment of the local community. Additionally, the logic of 'agglomeration', promoted by the Smart Specialization Strategy, if not properly accompanied by the incorporation of developmental poles into diffusion networks, leads to the rise of concentrated development patterns, which may have negative repercussions on local prosperity, contrary to the benefits that can be reaped from the potential synergies among different clusters.
Concerning the new Development Law for investment incentives (L. 4399/2016), this is moving in a different direction compared to EU's strategic framework. Primarily, it gives a small margin of maneuver to local entrepreneurs and thus very limited control of their area, in contrast to what RIS3 predicts. Moreover, it entirely ignores the significance of engaging local communities in decision making. Pursuant to the particular law, potential entrepreneurs are obliged to become involved in complicated bureaucratic procedures to submit their proposals in order for the latter to be evaluated by the central government. Therefore, the notion of presenting their ideas to the local authorities, who are the most affected by these entrepreneurial endeavors, is completely absent. Additionally, while promoting the development of balanced tourism activities throughout the country in theory, in reality both the Development Law and the SFSPD for Tourism impose considerable restrictions on tourism development. They often stress the need to tighten environmental constraints, as well as prevent the expansion of built-up space. However, no special care is taken for the areas that possess remarkable natural and cultural wealth, but they lag behind in terms of infrastructures, a relatively common situation in many regions of the Greek hinterland. The obvious conclusion is that such areas are compelled to enter the 'game' of providing high-quality services in the context of even stricter legislative frameworks for entrepreneurship. In any case, it is mandatory to secure the sustainable and rational exploitation of natural and cultural resources and any activity that takes place should respect them. This holds true especially for tourism, which considers a clean environment and rich cultural reserves as prominent productive factors. At the same time, the deployment of new, high-quality infrastructures in areas that aspire to competitively enter the tourism market should be substantially facilitated. Finally, only limited involvement/cooperation of the academic community with the business community is encouraged. Strengthening this bond is conducive to the pursuing of sustainable regional development trails by ameliorating and simplifying business processes; rendering environmental protection more effective, but not necessarily stricter; and advancing innovation. However, central planning seems to reject the creation of such dynamics while maintaining the Greek state as the only responsible body for the preparation, implementation and monitoring of the strategic plans. Nevertheless, the Greek strategic frameworks are partially in line with the European strategy.
Another critical remark relates to the fact that the SFSPD's updates were rejected by the Council of State in 2013, 2015 and 2017, which clearly indicates that the internal state does not function smoothly and that the bureaucratic inertia are expected to prevent or at least confine any future attempts to implement strategic interventions. This entails that significant investments, with reference to their overall impact, are required to be harmonized with the corresponding, but somewhat obsolete, legislative framework.
Finally, all the strategic spatial policy frameworks present their suggestions (on spatial interventions) in a rather equivocal and abstract way. They provide limited and, in many cases, out of date quantitative data, while the proposed goals and objectives are articulated in a very general manner, with vagueness rendering their outcomes non-causal in terms of target setting as well as non-measurable, and therefore unable of being subjected to any kind of assessment [52]. Thus, generality, ambiguity and non-binding nature lie at the heart of these spatial policy frames, thereby undermining their effectiveness in advance.

Assessing Spatial Repercussions of the Strategic Policy Frameworks in Enacting the Culture-Tourism Nexus
As previously mentioned, the already established tourism development of Greek areas has been acting as a decisive factor in the formulation of strategy and related policies towards its further thriving, guided, inter alia, by the ongoing pursuit of sustainable tourism development goals. Bearing the above statement in mind, this section attempts to make a critical comparison of the spatial dispersion of tourism-based entrepreneurial activities in each region with the spatial pattern of available cultural resources, which are perceived to be the 'vehicle' for the prosperity of tourism. The juxtaposition of these patterns demonstrates the degree to which the relevant resources have been utilized by the tourism business community towards developing different tourism forms (mass tourism or alternative).
In an effort to identify correlations between the spatial pattern of available cultural reserves and that of tourism entrepreneurial activities, the respective heat maps, i.e., the heat map of cultural resources (Figure 7a) and the heat map of tourism entrepreneurship ( Figure 5), were normalized and combined by means of spatial operations in order to compose a final, integrated heat map (Figure 7b). The resulting map (Figure 7b) reflects the intensity of the interrelationship between these two spatial phenomena, but also the extent to which availability of cultural resources has attracted tourism investments and facilitated the flourishing of widespread cultural tourism-oriented activities. The inspection of the spatial distribution of cultural resources (Figure 7a), the spatial dispersion of tourism activities ( Figure 5), and the combination of these two patterns (Figure 7b), leads to the following conclusions:

•
Cultural resources are almost evenly scattered throughout the country, with most areas possessing, to one degree or another, cultural wealth. In some cases, places that do not rely on tourism for their local prosperity, e.g., Larissa or Serres (mainland cities), exhibit, in terms of spatial density analysis of cultural data (but ignoring the magnitude of the resources), a dispersion akin to that of areas characterized by heavy tourism (e.g., Crete and the South Aegean). • At the same time, although these places are considered 'culturally equivalent', the spatial organization of tourism entrepreneurship, which expresses the degree of exploitation of cultural resources, follows a substantially different distribution. The prevalent spatial pattern is highly marked by a significant concentration of entrepreneurial activities in coastal and insular regions. It should also be noted that insular areas exhibit more intense spatial patterns compared to the coastal parts of the mainland.

•
The lack and, in many cases, absence of cultural tourism entrepreneurship observed in the Greek mainland suggests that the respective cultural resources have not managed to attract business interests thus far due to the low investment returns these are expected to deliver to the entrepreneurial community. This deficit is justified either by stringent terms and restrictions imposed on the exploitation of these resources (e.g., strict legislative frameworks) or by the nature of the promoted tourism development scheme per se, which may completely marginalize cultural heritage (e.g., the Sun-Sea-Sand model), since the latter is perceived as meaningless in relation to the blossoming of the former.

Assessing Spatial Repercussions of the Strategic Policy Frameworks in Enacting the Nature-Tourism Nexus
The overview of the spatial structure of natural resources (Figure 8a), the spatial distribution of tourism-related activities ( Figure 5) and their synthesis (Figure 8b) provides some valuable remarks:

•
All Greek territories are endowed with exceptional natural reserves, with the western and the southern part of the mainland displaying denser spatial concentrations. Moreover, mature and popular tourist destinations (mostly coastal and insular places) appear to possess poorer natural capital in comparison to those located in the Pindos-Peloponnese axis (mainland) and barely depend (or do not depend at all) on tourism. • National natural capital has made a subtle contribution to the development of respective tourism-based entrepreneurial activities. Empirical data on the Greek tourism sector, however, reveal that the natural beauty of landscapes acts as a complement to the enrichment and differentiation of the tourist product/experience.

Spatial Interelationship between the Nature-Culture Ensemble and Related Tourism Entrepreneurship
An analysis of the dispersion of natural and cultural resources (Figure 9a) in conjunction with the spatial organization of tourism entrepreneurship ( Figure 5) led to the generation of a combined heat map (Figure 9b), as well as to the following conclusions:

•
The whole of Greece is gifted with extraordinary natural and cultural resources that render the country an extremely significant environmental and cultural hub on a global scale. These resources are found, to one degree or another, in all Greek regions and constitute a remarkable reserve, which, when sustainably utilized and promoted, may be immensely conducive to regional development and substantially boost the national economy. Even areas with limited relevant resources but with long traditions and specialization in a particular field can take advantage of such opportunities, e.g., the Thessalian plain with agro-tourism or the city of Ptolemaida with educational and conference tourism for energy issues.

•
The spatial interrelationship between natural and cultural resources on the one hand and tourism entrepreneurship on the other, as is illustrated in Figure 9b, reveals the domination of intensified spatial concentrations of entrepreneurial activities in already established tourist destinations as well as the strong commitment to a traditional pattern of mass tourism development, the 'Sun-Sea-Sand' model.

•
Most of the regions in the hinterland, although possessing considerable natural and cultural capital, perform poorly in terms of forming a solid tourism-oriented entrepreneurial base. This is utterly paradoxical since mainland areas are, usually, equipped with more and better infrastructures and they are not confronted with the difficulties of coastal shipping, which adds an extra obstacle to physical transportation and diffusion of tourist flows. Furthermore, these regions are in closer proximity to the central European tourism markets (e.g., Germany and the United Kingdom) and are accessible by a greater variety of transport means (transnational highways, railways, etc.). In addition, mainland Greece offers a great wealth of resources of all kinds; it has a significantly larger population and access to a much more extended scientific base.

•
As regards the tourism-oriented entrepreneurial activities in the coastal and insular areas, these exhibit a great degree of diffusion and dense spatial distribution, regardless of their proximity to urban centers. They follow either a linear pattern, parallel to the coast, or cover whole islands. Conversely, in mainland Greece, tourism-based entrepreneurship is distributed around urban centers, thus creating a narrow buffer zone (a donut-like structure) or a small islet of tourism development that surrounds the urban fabric.

Discussion and Conclusions
Tourism is currently acknowledged as the world's largest industry and a main contributor to employment and destinations' wealth at a glocal level. Concurrently, it places the precious natural and cultural nexus at the core of its production process, capitalizing on it and creating challenging narratives and related products. In this respect, integrating current sustainability objectives, as defined by the UN Agenda 2030 and the specific SDGs paving humanity's sustainable next steps, into the sector's production process may substantially support the integrity of this valuable nexus, regarding both its tangible and intangible dimensions. In addition to the above, the very nature of tourism as a highly extrovert sector implies the need to continuously assess the rapidly changing external decision environment by grasping evolving key drivers of change and their potential impacts and properly adjusting the production processes and products in order to meet the sector's defined objectives.
In the current external decision environment, which shapes decision making in the tourism sector, sustainability appears to be the overarching goal. Climate change, a main source of current sustainability concerns but also an important barrier in the long journey towards effectively handling such concerns, is strongly linked to the above. Additionally, the sustainability and climate change discourse and their interrelationships have raised awareness and attached value to the culture-nature nexus and the manner in which this can be firmly integrated into the tourism sector in order to establish environmentally, culturally and socially responsible products as well as fair and equitable future tourism trails. Such an effort, as claimed by the policy science literature, is a cooperative one and is based on policy networks that engage local communities, tourism organizations, organizations representing other interests and governments at various spatial levels. Cooperation and decision-making outcomes of these networks are framed by the strategic policy guidelines, formulated by the central governmental institutions.
Therefore, by contextualizing the developments in the external environment as well as the challenges that need to be confronted by the emerging 'culture-tourism' complex in such an environment, and simultaneously considering the Greek strategic policy guidelines for the tourism sector and their outcomes in supporting the emanation of the above complex, the following key conclusions, which also briefly reply to the research questions raised in this paper, can be drawn:

•
The national strategic frameworks for tourism conform in one way or another to challenges of the external environment. However, they seem to fall short at the stage of implementation, thus hardly laying the ground for sustainable and resilient future development of this sector and its close intertwining with the remarkable naturalcultural nexus of Greece. Additionally, these frameworks do not seem to have given significant impetus to the respective entrepreneurial community to mobilize towards such a direction. • Very few areas, especially in mainland Greece, that are recognized by the strategic policy framework as appropriate for accommodating alternative in general and cultural tourism activities in particular have actually moved in this direction, i.e., attracting entrepreneurial interest and related nature-and culture-based tourism activities. • Coastal zones and insular regions still remain the main recipients of tourists who are eager to enjoy the 'summer myth' narrative of Greece. This, in turn, has already displayed the repercussions of the capacity limits being severely exceeded and overtourism patterns, thereby endangering the sustainable and resilient future of these places. These repercussions seem to be exerting increasing pressures in these regions due to the high seasonality that is a core attribute of the national tourist product. The Greek 'myth', built mainly upon the 'Sun-Sea-Sand' model, seems in fact to be critical in terms of the seasonality concerns of the tourism sector, but also a main decision factor for motivating tourism entrepreneurship towards taking action at specific, established tourist destinations.

•
The current strategic policy framework seems to fail in providing a positive outlook regarding a shift away from the 'summer myth' tourism developmental paradigm and the ongoing degradation of the natural-cultural nexus as well as the pressures exerted on local communities, an alarming phenomenon noticed especially in areas marked by overtourism trends.
Bridging the huge persistent gap between the current, well-established over time 'summer myth' model on the one hand and the model that is grounded in the 'culture-tourism' complex and the value attached to the nature-culture nexus on the other seems to appeal to more radical policy directions and related interventions. The formulation of such strategic policy directions and, more particularly, their successful 'on-the-ground' implementation call in fact for multi-level governance and multi-actor engagement in a process of co-designing more promising, place-specific 'culture-tourism' complex directions and motivating related entrepreneurship actions. Current planning approaches for sustainably exploiting natural and cultural reserves at the global level seem to stand for such management schemes of related resources. According to the above discussion, it is evident that although the national policy frameworks are taking steps towards redefining the Greek tourism strategy and affecting related entrepreneurship's locational decisions as well as overturning the image of the prevalent mass tourism model that emphasizes the triptych 'Sun-Sea-Sand' paradigm in islands and coastal areas, these efforts have not yet yielded the desired outcomes. Tourism-oriented entrepreneurship is detected mainly in the coastal zones of the country, either on the mainland or the islands, while extremely important natural and cultural resources, located in the hinterland, remain untapped and are therefore unable to be incorporated into the Greek tourist product over time and produce added value for the local and the national economy.
Such a mass tourism scheme that exclusively promotes coastal tourism-based products, however, fails to meet the current challenges of the external decision environment. More specifically, it is severely threatened by climate change impacts; it leads to unsustainable resource management that may produce demands beyond the capacity limits of local resources, thus defying sustainability concerns to the detriment of locals and visitors of tourism destinations; it fails to align with the newly emerging tourism market trends, i.e., the rapidly escalating demand for more personalized, peaceful, authentic and experience-based tourism products as well as developments in the supply side, taking the form of a quickly rising number of competing destinations, focusing on the aforementioned kind of tourism offers; and, finally, it proves rather weak in coping with severe external crises, such as the current health pandemic. Additionally, at the national level, such a model has substantial repercussions on social, economic and territorial cohesion, being a source of a completely asymmetric developmental pattern of both the sector and the Greek regions.
Obviously, a certain re-orientation as well as a natural and cultural turn of the tourism sector is necessary, taking into consideration the long history of Greece and the abundance of natural and cultural landscapes that witness this trajectory as well as the extraordinary beauty and diversity of its natural, land-and seascape. The repositioning of this sector will enrich it with a new flavor of culture and will add value to the developmental trajectory of Greece as a whole. Furthermore, it is expected to motivate the entrepreneurial community to undertake actions towards creating alternative tourism products that are matched to these resources, thus taking advantage of contemporary culture-related trends in the global tourist market. The rational exploitation of all local resources in combination with the creation of local and supra-local diffusion networks of tourist flows in a manner that could guarantee sustainability, resilience and balanced development of all areas would be the ideal scenario.
In brief, given the remarkable challenges that emerge from the external decision environment and the global tourism market, while also seeking to embrace more sustainable, resilient, authentic and experience-based tourism demand and supply patterns that are tightly interwoven with the abundant and precious natural and cultural heritage of Greece, the idea of sticking to 'traditional', inefficient and, in many cases, highly risky patterns of tourism development does not appear to be optimal. However, as the data-driven evidence of this work has shown, the transition to a more sustainable tourism model still remains an unresolved issue, and the need to re-design, re-orient and implement more promising strategic policy directions is apparent.
Towards this direction, the value of both the theoretical ground and the methodological approach followed in this work should be acknowledged.
The theoretical ground is characterized by the intersection of policy science, regional development and spatial planning disciplines. Each of these constituents serves particular goals and draw upon knowledge, tools and approaches emanating from these specific fields. Policy science provides the process ('how') through which policy decisions are articulated; regional development illuminates the 'goal' to be reached by addressing issues of social, economic and territorial cohesion ('regional inequalities') framed by the overarching goal of sustainability; while, finally, spatial planning delineates the spatial context of local/regional development goals ('where in space') and related specialization of policy decisions in alignment with each single developmental and resource availability spatial context.
The specific sectoral approach of this work, i.e., the focus on the tourism sector making more informed decisions with regard to a sustainable and resilient developmental pattern for this sector in alignment with current sustainability and cultural concerns, implies the need to assess the effectiveness of dedicated, directly or indirectly, tourism-related policy frameworks. The adoption of the 'policy cycle' as a methodological framework that guides such an effort in a systematic and well-structured way, coupled with spatial data management and mapping tools for collecting, elaborating and visualizing the natural and cultural resources on the one hand and tourism entrepreneurship on the other have proven quite effective in convincingly demonstrating current policy ineffectiveness in spatial and regional development terms. Such an outcome lays the ground for identifying the type and intensity of policy gaps and for properly informed policy remediation to motivate a harmonious, hand-in-hand coexistence of tourism with the culture-nature nexus in Greece, i.e., a highly endowed part of the world from a natural resource perspective and the cradle of global civilization.
Author Contributions: V.L., M.P. and A.S. have contributed to all aspects of this research, including the conceptualization and methodological approach. Additionally, V.L. provided greater contribution to data collection, processing, analysis, visualization, software and validation; M.P. contributed to developing the methodological framework and critically commenting on the results; A.S. contributed to the introductory and conclusion sections. All contributors have closely cooperated in writing, reviewing and editing the manuscript. All authors have read and agreed to the published version of the manuscript.