The Cultural Heritage and the Shaping of Tourist Itineraries in Rural Areas: The Case of Historical Ensembles of Extremadura, Spain

: Heritage is a very complex concept that is characterized by having multiple meanings. Despite this, there is no doubt as to its attraction for carrying out tourist activities. In the speciﬁc case of cultural heritage, there is widespread agreement in considering it as a tourist resource given the interest it raises amongst visitors of all origins. This is not, however, always the case and it can be observed that in certain areas, especially rural ones, certain limitations exist. They are caused by multiple factors such as the importance of the resource itself, although the distance to the main centers of tourist attraction is also considered a key point. Due to this, the study puts forward the need for joining forces and attractions in order to create tourist itineraries based on a peculiar kind of resource: Historical Ensembles. In order to achieve this aim, we used the network analysis tools included in a geographical information system and applied it to a rural context, which was that of Extremadura in Spain. To be precise, the closest facility and service area tools were used. The results of the various analyses reﬂect the real possibility of generating tourist itineraries as a ﬁrst step in the design of tourist products. In this way, the administration can be provided with a management tool capable of laying the foundations of a coherent and e ﬃ cient tourist policy.


Introduction
The meaning of heritage is complex. It can be understood as anything considered worth preserving, irrespective of the value of its use. Some authors consider it to be an invention and a social construction that has an effect on multiple levels such as political, scientific, or business [1]. It also includes both tangible and intangible elements [2]. Other authors have distinguished two nuances, one related to culture and nature and the other linked to the past of a society, although it only exists when this is highlighted. The legacy is thus linked to time and the use that is made of it [3,4].
In its conceptualization, the contributions that considered it to be an inheritance, a historical selection, a social identity, and a reference to the past stand out [5]. Likewise, numerous studies have treated the cultural landscape as part of heritage [6], with the main challenge being the maintaining of sustainability [7,8], especially if its transformation into a tourist resource is taken into account. It is also frequently considered to be an artistic attraction when it acquires a value and a significance [9], which is very difficult to understand given its quantity, diversity, and varied quality [10].
If this heritage is converted into a resource, it can be used to promote the socioeconomic and territorial development of the areas that contain it [11]. Indeed, cultural heritage has evolved from being a historical-artistic treasure to becoming a tourist resource of obvious value for its economic this ruling, the Ministry of Culture and Sports in Spain has created the General Register of Assets of Cultural Interest [40] and the General Inventory of Movable Property [41], which any citizen can freely access. These search engines allow for the downloading of a basic data sheet that identifies each of the assets on it and simultaneously provides a brief description and states their legal and administrative situation.
Naturally, heritage is located in many areas with its presence and attraction being outstanding in historical cities, although this richness is also found in the rural milieu. In this sense, it can be specified that Law 45/2007 of 13 December, on the sustainable development of the rural milieu, defines in Article 3 the rural milieu as the geographical space formed by the aggregation of municipalities or lesser local entities defined by the competent administrations as having a population of less than 30,000 inhabitants and a population density of less than 100 inhabitants per km 2 ; while a small rural municipality is considered to be one with a resident population of less than 5000 inhabitants and is located in the rural milieu [42]. The heritage present in the rural milieu has two clear orientations, culture and nature, although it is sometimes difficult to establish a clear limit between the two [43][44][45][46]. Despite this, the rural milieu tends to be associated with rural tourism, which concentrates particularly on the enjoyment of the environment [45][46][47] as can be gathered from the preferences declared by the rural tourists who visit Extremadura [48]. Cultural heritage may, however, play a key role in the development of these spaces [49]. Indeed, it can be observed that even in the rural milieu, a proportion of the tourists acknowledge their preference for activities strongly linked to cultural tourism [43].
The diversity of studies facilitates the treatment of varied aspects such as economic policy [50], sustainability [51,52], and even town planning [53]. Despite this, they tend to concentrate on the main historical cities; few studies have considered the rich heritage of rural settings, and even fewer have referred to the tourist exploitation of the cultural heritage in these areas. Furthermore, there is agreement in the literature on the perception of the rural environment as a genuine tourist space, which satisfies the experience of the tourist who visits it; this has been demonstrated in various spaces [54], although there are areas in which its cultural heritage is overshadowed [43].
The exploitation of heritage has popularized studies that have applied new tools and techniques with the aim of enhancing its attractiveness and consequently encouraging the attraction of new tourists. It can therefore be observed that some studies have used building information modeling (BIM) software to reproduce and rebuild important monuments of cultural heritage [55], although recourse is also had with augmented reality (AR) to promote heritage [56][57][58][59]. Nevertheless, this type of technology has been applied to monuments and sites that are clearly recognized as centers of tourist attraction, although it is not used for less visited areas. In addition, it has been observed that few specific studies exist on creating products based on tourist itineraries in areas of lesser tourist interest. Due to this circumstance, this study has chosen to generate a valid methodology for the design of itineraries to connect areas with various cultural resources with the aim of facilitating the setup of specific tourist products.
Cultural resources can be understood in a wide sense in the context of cultural landscapes, as can be inferred from the European Landscape Convention [60]. In this sense, the concept of landscape as set down in the Agreement expresses the wish to face-in a global and direct manner-the matter of the quality of the places where the population lives. This is recognized as an essential condition for individual and social welfare (understood in the physical, physiological, and intellectual sense), sustainable development, and as a resource encouraging economic activities [60] (p. 6). For this reason, it is clear that the presence of protected heritage assets is useful for promoting the socioeconomic development of outstanding areas, as occurs in rural spaces [61]. In these spaces, it is possible to find other cultural landscapes in addition to a considerable number of monuments such as dehesas [62,63] archaeological areas [64], water landscapes [65], etc. It can thus be observed that the landscape can be considered as both cultural and natural heritage, and a reason for continuous research [66]. Despite everything, it is well worth remembering that the application of the European Landscape Convention has been questioned in some cases [67].
Given the huge variety of historical heritage, we have had to limit our scope to a specific area, Extremadura in Spain, using a single type of real property as a reference: Historical Ensembles. In accordance with Article 15.3 of Law 13/1985 of 25 June on Historical Spanish Heritage, this consists of the grouping of real property, which makes up a continuous or dispersed unit of settlement, conditioned by a physical structure representing the evolution of a human community as it is a witness to its culture, or constitutes an asset of use and enjoyment for the group [39].
The main aim of this study consisted of determining the main centers of cultural attraction for visitors to Extremadura and creating tourist itineraries toward Historical Ensembles. In order to achieve this, it is necessary to be familiar with the motivations of tourists for travelling to this region as well as identify the most outstanding historical sites. With the use of a network analyst and its multiple possibilities, it will be possible to create different types of itineraries. The advantages of drawing up routes and their integration as a tourist product encourage the development of activity in places with relatively few overnight stays. At the same time, this approach combats the low level occupation of tourist establishments.

The Case Study
The study area selected for the research was Extremadura, Spain ( Figure 1), an eminently rural area with the exception of the main cities of Badajoz, Cáceres, Mérida, and Plasencia. Despite the fact that its tourist model has concentrated on cultural and natural tourism, it coincides with centers with a considerable heritage legacy [68], albeit with a clear preference for that of a cultural nature. This can be inferred from the publications issued periodically by the National Institute of Statistics [69], which provides information on travelers and overnight stays on its online portal (Table 1). Table 1. Main tourist parameters in the main centers of tourist attraction in Extremadura (2018). Despite the fact that its tourist model has concentrated on cultural and natural tourism, it coincides with centers with a considerable heritage legacy [68], albeit with a clear preference for that of a cultural ISPRS Int. J. Geo-Inf. 2020, 9, 200 5 of 29 nature. This can be inferred from the publications issued periodically by the National Institute of Statistics [69], which provides information on travelers and overnight stays on its online portal (Table 1). These data from official statistics show that tourism based on the cultural heritage of Extremadura is considerable, although it is highly concentrated in the World Heritage Cities and in other towns such as Badajoz, Plasencia, Trujillo, and Zafra [70].
The . These make up the backbone of our study.
The rich and well known heritage that characterizes these Historical Ensembles is mainly located in rural areas, with the exception of the cities that have been declared World Heritage Sites by UNESCO (Cáceres, Mérida, and Plasencia). The remainder of the 30 Historical Ensembles tend to be concentrated in certain areas such as the southwest of the province of Badajoz and the districts in the province of Cáceres of the Sierra de Gata, La Vera, and the Valle del Jerte, although they are not exclusively found in these areas.
The majority of these Historical Ensembles are among the most visited areas of Extremadura as 18 of them are centers of tourist attraction due to their high number of overnight stays. This fact is also corroborated by the number of beds that are concentrated in them. In contrast, tourists tend to visit the remainder, although they generate many overnight stays despite having various types of accommodation available ( Table 2).
The study area is faced with the inherent problem of many rural areas; its heritage is not generally highlighted for organized tourist practice, but the possibility of visiting these sites is left in the hands of the tourists themselves. This circumstance does not offer a tourist experience that can be extracted from these areas, and also generates impact, conditioning their lower tourism and economic development, which affects their demography. Indeed, part of the Historical Ensembles, for which the demand does not include overnight stays or at least in the proportion seen in others, have a population of less than 1000 inhabitants.

Methodology
The information that served as a basis for carrying out of the study comes from two well differentiated sources, depending on the type of data provided. In the first place, the cartographical information is from the National Geographical Institute (Instituto Geográfico Nacional, IGN) [71], which operates under the Creative Commons CC-BY 4.0 International License. It allows its free use for legitimate purposes with the sole obligation of acknowledging and mentioning the origin and ownership of the data. The work scale chosen was 1:100,000 as it is sufficiently detailed for the purposes of this research.
On the other hand, the information on accommodation comes from the Register of Tourist Companies of Extremadura [72], which was updated on 31 December, 2018 and makes up the database corresponding to the tourist establishments available. This alphanumeric database has been suitably georeferenced for its subsequent implementation in a geographical information system. In contrast, the information on the demand was obtained from a survey carried out throughout 2017 in tourist offices distributed all over Extremadura. This survey gathered information, which allows us to understand the structure of the demand and emphasizes the possibility of extracting a socioeconomic profile and a profile of tourist practices, among which the activity or activities that they take part in during their visit are of particular reference to this study. From these, it is easy to find out the type of tourism they practice. The following specific activities included learning Spanish; hunting; gastronomy; birdwatching; sky watching; participation in congresses or meetings; practicing sports; enjoying rivers, gorges, and reservoirs; practicing generic rural tourism; visiting wine cellars; visiting settings of films or TV series; visiting mines or caves and geological formations; and making cultural visits.
The methodology proposed for carrying out this study ( Figure 2) starts by obtaining the necessary information from the aforementioned sources. The procedure followed concerned both the cartographic and the numerical databases. Using these data, a GIS project was generated using the ArcGIS v.10.5 software. The cartography supplied by the National Geographical Institute (IGN) was used, although it was necessary to georeference the accommodation available with the aim of including it in the geographic information system. In contrast, the data on tourist demand came from a survey carried out throughout 2017 in the tourist offices of Extremadura. The database created from this survey contained 13,848 records, which were filtered according to the tourism type practiced and considering only the 33 Historical Ensembles, which left 6167 cases in the sample. The results obtained were georeferenced on the municipality of the overnight stay, irrespective of whether it was a Historical Ensemble or not, although in this case, the starting point taken was the 39 municipalities with the highest number of answers, which ensured greater reliability and rigor. Once the database was drawn up and passed into the geographical information system, we proceeded to determine the characteristics of the tourists who visited the protected spaces, taking into account that they must practice cultural tourism in isolation or in combination with other categories. Nevertheless, not all of these centers offered accommodation, although by means of field work, it was found that there were visitors who stayed in the vicinity. In this way, it was confirmed that Historical Ensembles were attractive to both the tourists who stayed in them and to the visitors who lodged in nearby places, as other studies on the area analyzed detected tourist mobility patterns on an isochrone of approximately 60 minutes [44,45], from which the interest of the demand gradually decreases.
After this confirmation, the possibility of creating tourist itineraries was considered by taking as a reference the most visited municipalities and the Historical Ensembles that would be viable, as it has been shown that tourist mobility patterns can be extracted [73][74][75][76]. From all of this, it can be gathered that the most visited municipalities (origin) and the Historical Ensembles (destination) were taken as a reference to establish the itineraries. In order to calculate the impedance on each of the 8,969 road sections, we decided to use the most usual average legal speeds for each road type. In this manner, in the case of dual carriageways, the speed was adjusted to 120 km/h (74 mph), A roads to 100 Km/h (62 mph), and minor roads to 90 km/h (55 mph), while in built-up areas, it was limited to 50 km/h (31 mph). The impedance values obtained were corrected by means of the travel time provided by the Viamichelin application [77] due to its greater precision. The main criteria taken in this route generator were as follows: travelling from the center of the city of origin to the center of the city of destination; taking Sunday traffic into account; and specifying 10 a.m. as the time of departure. Once the speeds had been established and the impedance obtained for each section, we constructed the network topology on which the two techniques included in the network analysis module integrated in ArcGIS were applied. These are the service area and closest facility. Once the database was drawn up and passed into the geographical information system, we proceeded to determine the characteristics of the tourists who visited the protected spaces, taking into account that they must practice cultural tourism in isolation or in combination with other categories. Nevertheless, not all of these centers offered accommodation, although by means of field work, it was found that there were visitors who stayed in the vicinity. In this way, it was confirmed that Historical Ensembles were attractive to both the tourists who stayed in them and to the visitors who lodged in nearby places, as other studies on the area analyzed detected tourist mobility patterns on an isochrone of approximately 60 min [44,45], from which the interest of the demand gradually decreases.
After this confirmation, the possibility of creating tourist itineraries was considered by taking as a reference the most visited municipalities and the Historical Ensembles that would be viable, as it has been shown that tourist mobility patterns can be extracted [73][74][75][76]. From all of this, it can be gathered that the most visited municipalities (origin) and the Historical Ensembles (destination) were taken as a reference to establish the itineraries. In order to calculate the impedance on each of the 8969 road sections, we decided to use the most usual average legal speeds for each road type. In this manner, in the case of dual carriageways, the speed was adjusted to 120 km/h (74 mph), A roads to 100 Km/h (62 mph), and minor roads to 90 km/h (55 mph), while in built-up areas, it was limited to 50 km/h (31 mph). The impedance values obtained were corrected by means of the travel time provided by the Viamichelin application [77] due to its greater precision. The main criteria taken in this route generator were as follows: travelling from the center of the city of origin to the center of the city of destination; taking Sunday traffic into account; and specifying 10 a.m. as the time of departure. Once the speeds had been established and the impedance obtained for each section, we constructed the network topology on which the two techniques included in the network analysis module integrated in ArcGIS were applied. These are the service area and closest facility.

Service Area
The procedure for creating a service area from a road network has been sufficiently described in the literature [78][79][80] and in the assistance provided by the software used [81], although a rough outline is given in Figure 3a,b.
ISPRS Int. J. Geo-Inf. 2020, 1, x FOR PEER REVIEW 9 of 31 (origin), which allows the accessibility of each of the Historical Ensembles (destination) to be measured, most of which are located in the rural milieu. Four categories were established in all. The first refers to the most visited centers, which are also Historical Ensembles, due to which the isochrone will be 0 minutes when it is carried out in the population center itself. The second includes Historical Ensembles found in a center other than that of the origin, but at a distance that can be covered in 20 minutes; the third category consists of those Historical Ensembles that are a maximum of 45 minutes away from the most visited centers; and finally, the fourth category consists of Historical Centers at a distance that takes over 45 minutes to cover. The four categories described allow for the determination of the facility of access to each Historical Ensemble and also allow for the determination of the number of beds available in each of the isochrones established, and which will be part of the potential offer.  The service area created on the road network allows for the obtaining of all areas and consequently of all the population centers within the isochrone specified. In order to do so, we chose to use two concentric service areas (20 and 45 min) that leave from the most visited centers (origin), which allows the accessibility of each of the Historical Ensembles (destination) to be measured, most of which are located in the rural milieu. Four categories were established in all. The first refers to the most visited centers, which are also Historical Ensembles, due to which the isochrone will be 0 min when it is carried out in the population center itself. The second includes Historical Ensembles found in a center other than that of the origin, but at a distance that can be covered in 20 min; the third category consists of those Historical Ensembles that are a maximum of 45 min away from the most visited centers; and finally, the fourth category consists of Historical Centers at a distance that takes over 45 min to cover.
The four categories described allow for the determination of the facility of access to each Historical Ensemble and also allow for the determination of the number of beds available in each of the isochrones established, and which will be part of the potential offer.

Closest Facility
The calculation of the nearest Historical Ensembles obtained the most suitable routes for travel from the main overnight stay centers, using as a criterion the two Historical Ensembles closest to the main tourist points. The technique used is a basic tool of any GIS and has a long history of scientific publications on very varied subject matters; it is very useful for showing the geographical accessibility of each site regarding certain services such as hospitals [82] or cash dispensers [83], or for calculating installations based on market sensitivity [84].
Although their use has spread as GISs have become more popular, the location of installations has been criticized because of the conception of the mathematical algorithms followed by each type of software and each application [85]. Due to this, for the purposes of this research, the algorithm integrated in ArcGIS was used.
The operation of the technique is simple as once the topology of the road network has been set up, it is only necessary to specify the number of locations near the areas of origin that must be sought (Figure 4a,b). In this case, the aim is to ascertain the two Historical Ensembles nearest to the main tourist points of Extremadura, supposing that given the average stay of less than 2 days [86], tourists cannot devote much time to internal travel.

Closest Facility
The calculation of the nearest Historical Ensembles obtained the most suitable routes for travel from the main overnight stay centers, using as a criterion the two Historical Ensembles closest to the main tourist points. The technique used is a basic tool of any GIS and has a long history of scientific publications on very varied subject matters; it is very useful for showing the geographical accessibility of each site regarding certain services such as hospitals [82] or cash dispensers [83], or for calculating installations based on market sensitivity [84].
Although their use has spread as GISs have become more popular, the location of installations has been criticized because of the conception of the mathematical algorithms followed by each type of software and each application [85]. Due to this, for the purposes of this research, the algorithm integrated in ArcGIS was used.
The operation of the technique is simple as once the topology of the road network has been set up, it is only necessary to specify the number of locations near the areas of origin that must be sought (Figure 4a,b). In this case, the aim is to ascertain the two Historical Ensembles nearest to the main tourist points of Extremadura, supposing that given the average stay of less than 2 days [86], tourists cannot devote much time to internal travel.

The Creation of Itineraries
The combination of the service area with the search for the nearest facilities allows for the creation of itineraries that are based on travel time and the presence of Historical Ensembles. This shows the possibilities of the combination of both techniques to put our faith in the development of itineraries as tourist products promoted from the most important overnight stay locations of Extremadura.
In order to create them, the first reference taken was the location of the main tourist points of Extremadura and subsequently, the maximum travel time to the nearest Historical Ensembles, taking the isochrone of 60 min as the limit ( Figure 5). This spatial configuration of the network allowed for the creation of an initial group of itineraries concentrated on the main tourist points and a second group that started from the remainder of the important tourist centers. The main limitation is that the routes must be generated by taking a single origin with multiple destinations. Due to this, in order to establish them correctly, we took each of the tourist points as an origin and all of the Historical Ensembles as destinations.

The Creation of Itineraries
The combination of the service area with the search for the nearest facilities allows for the creation of itineraries that are based on travel time and the presence of Historical Ensembles. This shows the possibilities of the combination of both techniques to put our faith in the development of itineraries as tourist products promoted from the most important overnight stay locations of Extremadura.

Tourist Types
The type of visitor received by Extremadura is very varied, although there is a predomination of those practicing cultural tourism in places where the heritage is considerable. In contrast, rural tourism predominates in upland areas and their vicinity, or in the major protected areas of the region. A clear relationship can therefore be observed between the type of resource that is characteristic of a In order to create them, the first reference taken was the location of the main tourist points of Extremadura and subsequently, the maximum travel time to the nearest Historical Ensembles, taking the isochrone of 60 min as the limit ( Figure 5). This spatial configuration of the network allowed for the creation of an initial group of itineraries concentrated on the main tourist points and a second group that started from the remainder of the important tourist centers. The main limitation is that the routes must be generated by taking a single origin with multiple destinations. Due to this, in order to establish them correctly, we took each of the tourist points as an origin and all of the Historical Ensembles as destinations.

Tourist Types
The type of visitor received by Extremadura is very varied, although there is a predomination of those practicing cultural tourism in places where the heritage is considerable. In contrast, rural tourism predominates in upland areas and their vicinity, or in the major protected areas of the region. A clear relationship can therefore be observed between the type of resource that is characteristic of a space and the type of tourist it attracts.
Both types of tourist can be differentiated from the activities each carries out and their relationship measured by means of Pearson's linear correlation coefficient (Table 3).  Despite the fact that cultural tourism was defined during the 22 nd Session of the General Assembly held in Chengdu, China (11-16 September 2017) as "A type of tourism activity in which the visitor's essential motivation is to learn, discover, experience and consume the tangible and intangible cultural attractions/products in a tourism destination. These attractions/products relate to a set of distinctive material, intellectual, spiritual and emotional features of a society that encompasses arts and architecture, historical and cultural heritage, culinary heritage, literature, music, creative industries and the living cultures with their lifestyles, value systems, beliefs and traditions", defining cultural tourism is not always easy [87].
The tourist profile can be obtained from the activities they carry out. In this way, the cultural tourist is a visitor who wishes to learn Spanish, seeks gastronomic opportunities, participates in events such as congresses, visits wine cellars or film settings, and naturally makes cultural visits. In contrast, the rural tourist can be defined as one who practices hunting, birdwatching or sky watching, sports, or enjoys activities in rivers and reservoirs, in addition to those who practice genetic rural tourism or visit geological formations.
The territorial distribution of both generic tourist types in the case of the most visited destinations reflects the fact that in certain places, the proximity of the heritage resource does not coincide with a high percentage of those practicing cultural tourism ( Figure 6). There are areas in the north of the province of Cáceres in which cultural tourism is not so important, despite the presence of a considerable cultural heritage. This situation is due to the fact that these areas have outstanding natural resources and are particularly orientated toward summer tourism because they have bathing areas and milder temperatures, complemented by important marketing campaigns and the proximity to large centers generating tourists such as Madrid [48]. In other areas, there is a noticeable balance between cultural and rural tourism, as is the case in the Villuercas-Ibores-Jara Geopark, exemplified by the centers of Cañamero and Guadalupe. In contrast, the province of Badajoz is characterized by a clear predominance of cultural tourism. From all of this, two interesting aspects can be inferred. The first is the diversity of activities carried out by rural tourists, which may serve as a basis for integrating them in a potential tourist product as occurs with gastronomy, for example. The second is based on the territorial diversity of rural tourists who predominate in some areas, rather than in others.

Historical Ensembles as Potential Centers for Attracting Demand (Service Area)
Historical Ensembles act as true centers of tourist attractions. However, their capacity to attract visitors lies in their proximity to the main centers of tourist attraction in Extremadura, in addition to their importance and the confluence of further recognition by the Ministry of Culture and UNESCO. For this reason, the service area was calculated with two different isochrones corresponding to oneway travel lasting 20 and 45 minutes. Moreover, it should be pointed out that certain Historical Ensembles coincide with the most visited centers; in these cases, the travel time was considered to be zero. Likewise we included all centers that are Historical Ensembles, but at a greater travel distance. Four categories were therefore recognized according to the travel time from the most important tourist centers (Table 4).

Historical Ensembles as Potential Centers for Attracting Demand (Service Area)
Historical Ensembles act as true centers of tourist attractions. However, their capacity to attract visitors lies in their proximity to the main centers of tourist attraction in Extremadura, in addition to their importance and the confluence of further recognition by the Ministry of Culture and UNESCO. For this reason, the service area was calculated with two different isochrones corresponding to one-way travel lasting 20 and 45 min. Moreover, it should be pointed out that certain Historical Ensembles coincide with the most visited centers; in these cases, the travel time was considered to be zero. Likewise we included all centers that are Historical Ensembles, but at a greater travel distance. Four categories were therefore recognized according to the travel time from the most important tourist centers (Table 4). There are a large number of Historical Ensembles scattered over a large proportion of Extremadura (Figure 7), of which 17 (51.5%) are among the most popular tourist destinations of Extremadura and make up category 1. Indeed, it is made up of the population centers receiving most of the tourists and that have a Historical Ensemble. Among them, Cáceres and Mérida stand out as both have been declared World Heritage Sites as well as Guadalupe, as its monastery is part of this same Heritage. Together with other towns such as Plasencia, Trujillo, Zafra, Jerez de los Caballeros, and Hervás, they are icons of the rich cultural legacy of Extremadura and attract many visitors. It was found that during 2018, if we only included the statistics of the hotel accommodation at the main tourist points, the city of Cáceres was visited by 289,496 people, Mérida by 246,852, and Badajoz by 209,509, while Plasencia, Trujillo, and Zafra attracted less than 100,000 travelers [86]. Evidently, a large proportion of these population centers is attractive to tourists and day trippers, with the outstanding cities that are World Heritage Sites, although in others that are smaller and less attractive, tourist itineraries could be drawn up to connect them with other centers that also have quality tourist resources.
Category 2 is made up of the Historical Ensembles that are located no more than 20 min away from the main tourist centers. It contains three Historical Ensembles: Garganta la Olla, Pasarón de la Vera, and Valverde de la Vera, with a travel time between them of 56 min and on which route or in the vicinity of which are found other centers such as Cuacos de Yuste and Villanueva de la Vera.
Category 3 is made up of centers that are rather further away and included in the isochrone of 45 min. These are the Historical Ensembles of Burguillos del Cerro, Feria, and Hoyos, which are far from each other, but are near other areas that receive many visitors.
Finally, Category 4 consists of 10 centers at a distance of over 45 min from the main cultural tourist destinations of Extremadura. Despite this, they are very attractive and are equally close to other Historical Ensembles, which increases their attraction, provided that a circuit or tourist itinerary is generated and enhanced by means of a cultural tourist product. The beds available in the various types of accommodation present in the categories drawn up reflect two outstanding aspects (Table 5). In the first place, it corroborated that there is a large pool of lodgings in the municipalities that have a Historical Ensemble. They accounted for 39.8% of the total number of beds, however, the figure for hotel accommodation was over 48%, non-hotel accommodation was 36.2%, and rural accommodation was scarcely 26%. Despite the fact that we were concerned with a high number of beds in only 33 municipalities of the 388 in Extremadura, it should be stressed that three of them (Cáceres, Mérida, and Plasencia) accumulated 46.7% of the beds of the same. Second, it was detected that 17.3% of the beds available in rural accommodation located in municipalities that have been declared Historical Ensembles were less than 45 minutes travel time by road from the main overnight stay centers, a percentage that rises to 28.4% of the rural accommodation available when the isochrone of 45 minutes is exceeded.  The beds available in the various types of accommodation present in the categories drawn up reflect two outstanding aspects (Table 5). In the first place, it corroborated that there is a large pool of lodgings in the municipalities that have a Historical Ensemble. They accounted for 39.8% of the total number of beds, however, the figure for hotel accommodation was over 48%, non-hotel accommodation was 36.2%, and rural accommodation was scarcely 26%. Despite the fact that we were concerned with a high number of beds in only 33 municipalities of the 388 in Extremadura, it should be stressed that three of them (Cáceres, Mérida, and Plasencia) accumulated 46.7% of the beds of the same. Second, it was detected that 17.3% of the beds available in rural accommodation located in municipalities that have been declared Historical Ensembles were less than 45 min travel time by road from the main overnight stay centers, a percentage that rises to 28.4% of the rural accommodation available when the isochrone of 45 min is exceeded.
Analysis of the service areas revealed that there were a large number of beds in the historical ensembles near the most visited tourist points of Extremadura. This proximity allows for the offering of specific products in the form of tourist itineraries, which could increase the percentage of occupation of the establishments, which in the case of rural accommodation in 2018 was 18.13% and 34.75% on the weekend. Likewise, the level of occupation of hotels could be increased (their average figures varied between 36.24% and 47.06%), or even that of tourist apartments, which have an average occupation rate of 34.12% [86].

Nearby Historical Ensembles as Areas of Expansion for the Tourist Experience (Closest Facility)
Numerous authors have shown that tourists move about the area near their overnight stay site [43,45,88,89] and between various destinations [90,91]. In this sense, the existence has been demonstrated of Historical Ensembles, which have the competitive advantage of being located close to the main tourist points of Extremadura. At the same time, it has been corroborated that there are other centers that lack these advantages as they are located on an isochrone exceeding 45 min of travel time, which would place them at the limit of the mobility that the tourist can assume, as has been found by some studies that revealed a considerable drop in the arrival of visitors from the main destinations when travel time exceeded 60 min. It is in these cases, when outgoing or return journeys to their places of residence are made use of to make short stops in these areas [45]. Due to this, it is interesting to design tourist itineraries capable of attracting visitors from the vicinity and to expand the economic benefits generated by tourism, especially when these other destinations are located in the rural milieu with the added problems that this entails.
Under these premises, it was decided to determine whether tourists stayed about two days in the accommodation establishments located in the main tourist areas [92] and they did not go far to explore the vicinity. For this reason, the Historical Ensembles closest to the overnight stay site were found, even though half of them coincided with the most visited sites.
The most significant results obtained with the closest facility application imply that there were 78 possible routes from the overnight stay points (39) to the two nearest Historical Ensembles (33) ( Table 6).
A detailed analysis of the Historical Ensembles close to the most important tourist centers shows that in addition to the 17 that coincided with the most visited centers, there were 45 possible routes located at the limit of the isochrone of 45 min. Moreover, it is logical to think that the nearest were those with the best opportunities for receiving visitors. On the other hand, there were 16 other possible routes with a travel time exceeding the threshold of 45 min. It is therefore feasible to design historical itineraries to link the most visited municipalities with Historical Ensembles in a reasonable time for tourists, thus encouraging the development of the adjoining areas ( Figure 8). The main tourist centers, having a heritage considered to be a Historical Ensemble, are in a better position to generate a tourist route, especially if another center with a considerable cultural heritage lies in the vicinity. In this sense, the most favored are: Alburquerque, Alcántara, Azuaga, Cabezuela del Valle, Cáceres, Coria, Guadalupe, Hervás, Jerez de los Caballeros, Llerena, Mérida, Olivenza, Plasencia, Trujillo, Valencia de Alcántara, Villanueva de la Vera, and Zafra. These historical ensembles are capable of attracting numerous visitors on their own accord, although Cáceres, Mérida, Trujillo, and Plasencia stand out for their capacity of attraction. Moreover, it so happens that some of them are also located on the isochrone of 20 min from others, as is the case of Cabezuela del Valle, Guadalupe, Hervás, Plasencia, and Zafra. In other words, these centers have their own Historical Ensemble and another very close to it to take advantage of the territorial synergies that tourist activities allow.
Other municipalities that have a historical ensemble, but are not among the most visited are, however, no more than 20 min by car from the main tourist points of Extremadura, which can bring them visitors who spend the night nearby. These include Cuacos de Yuste, Fuente del Maestre, Galisteo, Garganta la Olla, Magacela, and Valverde de la Vera. This group of towns is accompanied by others that are more than 20 min from the most visited centers, although they are not more than 45 min away by car. These are Burguillos del Cerro, Fregenal de la Sierra, Fuente del Maestre, Galisteo, Garganta la Olla, Gata, Granadilla, Llerena, Pasarón de la Vera, Trujillo, and Valencia de Alcántara. The main tourist centers, having a heritage considered to be a Historical Ensemble, are in a better position to generate a tourist route, especially if another center with a considerable cultural heritage lies in the vicinity. In this sense, the most favored are: Alburquerque, Alcántara, Azuaga, Cabezuela del Valle, Cáceres, Coria, Guadalupe, Hervás, Jerez de los Caballeros, Llerena, Mérida, Olivenza, Plasencia, Trujillo, Valencia de Alcántara, Villanueva de la Vera, and Zafra. These historical ensembles are capable of attracting numerous visitors on their own accord, although Cáceres, Mérida, Trujillo, and Plasencia stand out for their capacity of attraction. Moreover, it so happens that some of them are also located on the isochrone of 20 minutes from others, as is the case of Cabezuela del Valle, Guadalupe, Hervás, Plasencia, and Zafra. In other words, these centers have their own Historical Ensemble and another very close to it to take advantage of the territorial synergies that tourist activities allow.
Other municipalities that have a historical ensemble, but are not among the most visited are, however, no more than 20 minutes by car from the main tourist points of Extremadura, which can bring them visitors who spend the night nearby. These include Cuacos de Yuste, Fuente del Maestre, Galisteo, Garganta la Olla, Magacela, and Valverde de la Vera. This group of towns is accompanied by others that are more than 20 minutes from the most visited centers, although they are not more than 45 minutes away by car. These are Burguillos del Cerro, Fregenal de la Sierra, Fuente del Maestre, Galisteo, Garganta la Olla, Gata, Granadilla, Llerena, Pasarón de la Vera, Trujillo, and Valencia de Alcántara. This analysis emphasizes the existence of various competitive advantages among the historical ensembles, always taking into account the proximity to the most popular tourist centers. This would facilitate the creation of specific routes orientated toward excursions.

Designing Cultural Itineraries in the Rural Milieu
The use of the service area and closest facility shows that there are genuine possibilities of creating tourist itineraries directed from each of the most visited centers toward the Historical Ensembles. The starting point is that of itineraries combining duration and the number of possible destinations, taking into account the time available as the average stay tends to be less than two days [85].
In order to make the calculation, we took as a reference a maximum distance of 60 min from the center of each tourist point to the center of each Historical Ensemble. The result was 116 possible routes starting from a total of 22 tourist points and leading toward 31 Historical Ensembles, some of which were outside the isochrone established.
The Historical Ensembles that can most benefit from the creation of tourist itineraries are those linked to the tourist points that capture the most demand and are the nearest. These were Cáceres, Mérida, Badajoz, Plasencia, Trujillo, and Zafra (Table 7). Their territorial distribution ( Figure 9) shows that with the exception of Badajoz, they had a Historical Ensemble. At the same time, it was observed that some centers can offer a considerable number of itineraries, as is the case of Plasencia or Zafra. These towns also generate itineraries that can even reach two Historical Ensembles on the same route, with the advantages that this brings when creating a specific tourist product.
The 32 itineraries created have a different development and success potential as in some cases, a Historical Ensemble is also a World Heritage Site. In other cases, the attraction of the historical site itself is different, to which must be added other elements such as the reputation of the area in which it is located and naturally the travel time.
Any of the routes including the cities of Cáceres or Mérida are clearly more attractive, with Trujillo being the center, which benefits most, given its proximity to Cáceres. Travel time must also be taken into account as the nearest ensembles will be those with the most competitive advantages. In this case, Plasencia, one of the most visited centers of Extremadura, can generate itineraries with some 30 min of travel time to Galisteo and Coria as well as to Pasarón de la Vera, Hervás, and Cabezuela del Valle, which are also outstanding tourist destinations. A similar situation can be found in Zafra, with the nearby sites of Fuente del Maestre, Burguillos del Cerro, and Feria, in addition to those of Llerena, Fregenal de la Sierra, and Jerez de los Caballeros, which are rather further away.
In this case, Plasencia, one of the most visited centers of Extremadura, can generate itineraries with some 30 minutes of travel time to Galisteo and Coria as well as to Pasarón de la Vera, Hervás, and Cabezuela del Valle, which are also outstanding tourist destinations. A similar situation can be found in Zafra, with the nearby sites of Fuente del Maestre, Burguillos del Cerro, and Feria, in addition to those of Llerena, Fregenal de la Sierra, and Jerez de los Caballeros, which are rather further away. The remainder of the overnight stay places can also benefit from the creation of specific itineraries; those that are already Historical Ensembles have competitive advantages as they attract a specific demand which is that of cultural tourism (Table 8). This is the case of Guadalupe, Hervás, Jerez de los Caballeros, Olivenza, and Valencia de Alcántara. Nevertheless, the travel time necessary to reach other historical places must also be taken into account. The remainder of the overnight stay places can also benefit from the creation of specific itineraries; those that are already Historical Ensembles have competitive advantages as they attract a specific demand which is that of cultural tourism (Table 8). This is the case of Guadalupe, Hervás, Jerez de los Caballeros, Olivenza, and Valencia de Alcántara. Nevertheless, the travel time necessary to reach other historical places must also be taken into account.
A detailed analysis of the 84 itineraries obtained from the 16 secondary tourist points reflects a differentiated casuistry. Perhaps the most noteworthy aspect is that many itineraries involved relatively lengthy travel, which often exceeds the isochrone of 45 min such as those of Caminomorisco and Guadalupe. Despite this, some itineraries were very well marked such as those that can be generated between Alange and Mérida, which are part of the Roman Archaeological Site of Mérida and are barely 26 min apart. Other cases of very short routes are those between Baños de Montemayor and Hervás (8 min); Don Benito and Magacela (14 min); Jerte or Navaconcejo and Cabezuela del Valle (5-6 min), and Malpartida de Plasencia and Galisteo or Plasencia (14-16 min). Together, it can be seen that other itineraries explore the district of La Vera starting from Jarandilla de la Vera and with their final destination being five Historical Sites on routes with a travel time of about 30 min. At the other extreme, we have Caminomorisco, which is at least 45 min from any other place of historical interest.
The territorial distribution showed two major concentrations of viable itineraries corresponding to the north of the province of Cáceres and the south of Badajoz. This circumstance may favor the creation of longer itineraries and in this way fight against the short average stay, which characterizes most of the tourist accommodation of both spaces. On the other hand, it was also shown that some Historical Ensembles are not part of the circuits as their travel times exceed one hour, as in the case of Guadalupe and Azuaga. Likewise, other itineraries can be appreciated, which are very isolated in the territory; the most representative case is that of Valencia de Alcántara ( Figure 10).

Alcántara 55
The territorial distribution showed two major concentrations of viable itineraries corresponding to the north of the province of Cáceres and the south of Badajoz. This circumstance may favor the creation of longer itineraries and in this way fight against the short average stay, which characterizes most of the tourist accommodation of both spaces. On the other hand, it was also shown that some Historical Ensembles are not part of the circuits as their travel times exceed one hour, as in the case of Guadalupe and Azuaga. Likewise, other itineraries can be appreciated, which are very isolated in the territory; the most representative case is that of Valencia de Alcántara ( Figure 10).

Discussion
The rapid implementation of technological advances is becoming more and more relevant in cultural tourism. Numerous studies incorporate conceptual models designed to improve tourist experiences by means of immersive technology [93,94] such as augmented reality [95,96]. Use is also made of the analysis of the information provided by social networks to detect mobility patterns [97].

Discussion
The rapid implementation of technological advances is becoming more and more relevant in cultural tourism. Numerous studies incorporate conceptual models designed to improve tourist experiences by means of immersive technology [93,94] such as augmented reality [95,96]. Use is also made of the analysis of the information provided by social networks to detect mobility patterns [97].
It is obvious that there is a strong technological bid for the development and improvement of tourist experiences. However, few studies have explored methods for generating tourist itineraries to which the technological innovations mentioned are subsequently applied [44,45]. To a certain extent, the impression given is that the itineraries arise spontaneously, without taking into account other criteria regarding the specific demand of each territory and the time available or the necessary travel. Perhaps more importance is attached to the technique than basic knowledge when the reverse should be true.
Given this situation, the research proposes a methodology that allows for the creation of itineraries, taking as basis criteria the proximity and travel time, in addition to the presence of resources. In order to demonstrate its potential, we have taken as a basis a specific area that counts on a peculiar kind of resource, Historical Ensembles. Numerous studies emphasize that this kind of tourist attraction can capture a large number of visitors and day trippers. In order to achieve this, it is necessary to create specific itineraries that offer the potential tourist the possibility of getting to know the nearby heritage in a coordinated manner by means of a tourist product. This idea has been put forward by numerous authors at very different times [98][99][100][101], and is of particular interest in areas with a considerable scattered cultural heritage that are not in themselves capable of attracting numerous tourists.
In the context analyzed, the creation of itineraries arises as a basic need for encouraging tourism as can be seen on numerous official websites, although an exhaustive classification of these has not been carried out in the study area [102]. On occasion, the itineraries do not arise from specific analyses based on methods, but are rather the result of improvisation [45] or do not even exist. A lack of the same constitutes a clear limitation of the development of the activity [103] as they may form cultural corridors to multiply the added value of a destination. This aspect is essential when the resources are not sufficiently attractive to generate tourist flows and must be supported by other resources, if they are to be competitive and capture visitors. As a consequence, the study carried out aims to lay the foundations of what may be a valid methodology for highlighting the cultural heritage of many areas. In order to achieve this, we resorted to a GIS, a tool frequently used in the analysis, management, and planning of tourism [104][105][106]. To be precise, the study concentrated on the use of the network analyst, a specific tool that allows for the calculation of service areas and the closest facility. Both analyses generate itineraries starting from a series of facilities and incidents to facilitate decision-making and tourist management.
The application of the network analyst allows for the creation of numerous routes and their prioritizing in accordance with the criteria indicated, either because of the importance of the tourist point from which they start, or the proximity of other potential destinations. It is therefore made clear that not all of the possible routes will be viable due to the necessary travel time, which means that they are limited. This shows that it is possible to generate tourist itineraries on which to begin studies of economic viability and to promote the creation of products that combine experiences in different places. From these, it will be possible to apply all the technological innovations that are beginning to become widespread in the tourist sector such as augmented reality, big data [107], and even artificial intelligence [108].
The results obtained in this study show that it is possible to create itineraries, provided that certain minimum conditions are met such as being aware of the location of the resources and the main centers of tourist attraction as well as the road network. In its turn, with the introduction of the necessary adjustments, it is possible to reproduce the methodology with other tourist resources and in other places. It was corroborated that Historical Ensembles are centers of tourist attraction that can benefit from joint interaction by the implementation of tourist itineraries. Likewise, it is emphasized that it is possible to manage and plan these itineraries by adjusting the selection criteria, either of the kind of resource or the travel time that tourists wish to devote to getting to know the vicinity.
The usefulness of this research is focused on demonstrating the potential of Extremadura for the creation of cultural itineraries and facilitation of the comprehensive management of the same. It thus aims to be a work base on which to encourage the tourist development of rural areas by highlighting their cultural heritage. For this reason, numerous actions are necessary to create products orientated toward excursions, which are offered at the main points of tourist attraction. Subsequently, it will be necessary to create products focusing on tourists spending the night at the various points that make up an itinerary.
The results obtained open up future lines of research involving ascertaining the preferences of demand in such a way that the generation of itineraries based on specific resources can be further specified. In this case, the methodology would clear the way for the creation of itineraries based on castles, megaliths, etc. In the same manner, another line could be opened up to lead to the generation of products highlighting the itineraries created to feature the availability of accommodation and restaurants, tourist guides, etc.

Conclusions
The main conclusions that can be drawn from this research are diverse. The first reveals that although the type of tourists who visit Extremadura varies greatly, they can clearly be placed in two categories: those with cultural preferences and those who identify with the natural milieu. Moreover, the territorial distribution does not always adapt to the presence of certain resources. It has thus been detected that some areas contain a considerable cultural heritage, but cultural tourists do not predominate there, which casts a doubt as to whether their tourist exploitation is satisfactory.
The second shows that the cultural heritage of Extremadura is one of the essential resources for tourist development. Despite the extraordinary richness of the heritage, only a few tourist centers are capable of highlighting it. Indeed, these tourist points are noted for their capacity of capturing tourists and are characterized by being Historical Ensembles, although the most outstanding are the World Heritage Sites of Cáceres and Mérida. It can, however, be appreciated that other centers exist, which do not attract a significant volume of visitors, despite the fact that they are Historical Ensembles.
The third stresses the need to create tourist itineraries capable of multiplying the attraction of certain centers, which is necessary when a single municipality is incapable of attracting visitors on its own accord. The creation of these itineraries is always complex and on occasion, may be ambiguous; indeed some authors maintain that tourist routes themselves may be both a resource and a product [109,110]. Nevertheless, the study has shown that cultural tourism is particularly attractive in Extremadura as is borne out by the large number of tourists and overnight stays recorded in its main heritage towns. For this reason, it is thought necessary to stress the expansion of the development of activity toward areas that are not on the tourist market.
The fourth shows the use of GISs to generate these itineraries, taking as a basic tool the network analyst and combining the analytical possibilities it offers. There is no doubt that GIS tools have become very popular for the analysis and management of the territory, especially when they offer a huge potential for facilitating the taking of decisions. Indeed precedents exist that defend their role as a management tool [111,112] and as necessary software for the creation of tourist itineraries and the discovery of mobility patterns [44,70]. Likewise, it has been stressed that it is a simple matter to create tourist itineraries by using these network analysis tools, but it cannot be denied that it is also possible to develop the routes much further to adapt them to the requirements considered appropriate by managers. In this sense, both the closest facility and the service area tool have been shown to be efficient.
The fifth concentrates on the discrimination of itinerary types taking into account basic aspects of the origin and the destination in addition to the travel time. If the essential results are considered, it is clear that there are areas in which it is very easy to generate and highlight an itinerary when some Historical Ensembles are a very short distance from others. In contrast, other areas find it very difficult to establish routes due to their peripheral position or their poor accessibility, which means that they depend on their own action to capture tourists.
The sixth and last conclusion that can be drawn is the need to establish as a starting point the design of itineraries to offer competitive products in areas that are not in the best position for tourism due to external determinants such as their location or accessibility [113]. Naturally, the final design of the itinerary and its conversion into a resource needs further study to measure the attraction capacity of the territory using specific assessment techniques for both demand and supply. Funding: This publication is part of the research carried out within the research project "Diseño y elaboración de productos estratégicos diferenciados para la potenciación del turismo rural en Extremadura. De la detección de problemas a la propuesta de soluciones basadas en criterios geoestadísticos" (Code IB 16040). This Project was funded by the Consejería de Economía e Infraestructuras de la Junta de Extremadura (the branch of the regional government that covers economy and infrastructure) and by the European Regional Development Fund (ERDF). This work was supported by Junta of Extremadura and co-financed by the European Regional Development Fund through GR18052 (DESOSTE).

Conflicts of Interest:
The authors declare no conflicts of interest.