Mapping Decay: A GIS-Based Assessment of Historic Defensive Heritage and Its Latent Landscape in Castellón, Spain

Abstract

This study examines how the values of authenticity and integrity can be integrated into territorial and landscape planning, moving beyond a restoration-based view of heritage. It focuses on the defensive architecture system of Castellón province (Spain), which features around 150 fortifications forming a continuous landscape between coastal and inland areas. In a context of urban pressure, rural depopulation, and heritage tourism, this research explores how the management of these assets can be aligned with coherent territorial strategies. The aim is to assess the material, visual, and symbolic coherence of the system and to understand the tensions between physical conservation, cultural authenticity, and landscape transformation. The methodology combines documentary review, spatial analysis using GIS, and fieldwork, applying qualitative indicators of material authenticity, territorial integrity, and scenic value adapted from ICOMOS guidance and established scientific literature. The results reveal a clear contrast: 62% of urban castles are restored or consolidated, while 71% of rural ones remain in ruins, and 82% preserve high visual integrity. This paradox shows that heritage sustainability is less dependent on formal reconstruction (only 14% are fully restored) than on maintaining relationships between architecture, environment, and community. This study proposes an integrated territorial management approach that links conservation, use, and landscape as interdependent components of a single cultural system.

1. Introduction

Defensive architecture, a striking feature of the European landscape, unites military function, political symbolism, technical knowledge, and collective memory. Castles in particular embody material and immaterial values. They are symbols of power, identity, and territorial control, but also sites of transformation, ruin, and reinterpretation. Today, their study extends beyond archaeology or style, moving into the field of heritage theory, where authenticity, integrity, and scenic value are key to the process of conservation interpretation and diagnosis [1,2,3].

In recent years, the debate on authenticity has been subject to intense scrutiny. From the Nara Document [4] to recent works by Nakonieczna and Szczepański [5] and Milojković et al. [6], views have shifted from an essentialist notion of material originality to a dynamic, pluralistic interpretation. This new approach recognises layers of meaning, memory, and use. Authenticity is increasingly defined as a relational condition grounded in cultural continuity rather than material permanence [7]. Heritage assessment therefore extends beyond materials to include historical legibility, landscape coherence and the social perception that maintains a sense of place [8,9,10]. However, despite the extensive theoretical debate, there remains a lack of applied territorial studies capable of operationalising these concepts, and the defensive landscape of Castellón provides an exceptional laboratory due to its density, typological diversity, and contrasting patterns of conservation.

Furthermore, integrity is no longer understood as physical completeness but as the coherence between a property and its constituent parts. Recent frameworks, such as the ICOMOS Guidance on Heritage Impact Assessments [11] and Ashrafi et al. [12], relate integrity to the functional, spatial and visual continuity of a site. For castles, this involves assessing both the surviving structures and their topographical, visual and symbolic relationships with the territory. Loss of integrity therefore includes not only ruin but also the visual or functional dissociation from context, a condition especially evident in rural landscapes affected by abandonment or unsuitable interventions [13,14].

In this sense, ruin acquires an epistemological value. As Lowenthal observes [15], deterioration involves not only loss but also documentation, turning worn material into a temporal archive. Far from signalling failure, ruins embody the historic nature and evocative power of material culture [16,17]. Castles should therefore be evaluated not only for their conservation state but for the authenticity conveyed through incompleteness. Ruin thus becomes both a cognitive and aesthetic category, mediating between degradation and permanence [18].

Recent heritage research highlights the need to integrate landscape and scenic values into conservation assessments. The landscape is not a neutral backdrop but a constitutive element of heritage, shaping perception, symbolic orientation and community attachment [19,20]. From this perspective, castles operate as ‘nodes of visibility’ [21], organising space, guiding the gaze and conveying identity. Studies on European fortified landscapes further underscore the role of visual integrity as a dimension of authenticity [6] while warning that contemporary developments or environmental transformations can erode scenic value and fragment interpretation [14,22,23].

In this study, visual integrity is operationalized as the degree of coherence between each fortification and its surrounding landscape, assessed through the legibility of the setting, the continuity of historical viewsheds, and the absence of major visual barriers or contemporary intrusions.

Recognition of scenic value is not limited to aesthetic contemplation; it also presents perceptual and emotional dimensions. Research on perceived authenticity in heritage contexts [13,24] shows that the visitor experience is an active component of conservation, where visitors’ understanding, emotion, and sense of belonging play a key role. Heritage is therefore not limited to its materiality; it is also a social practice renewed in the gaze and narrative. This phenomenological perspective, reinforced by trends in the field of heritage studies [17,25,26], prompts us to rethink diagnosis: it is not only a technical act, but also an interpretative assessment of the cultural values defining the property. On this point, the proposals of Bandarin and van Oers [27] and Xie et al. [28] reinforce the idea that authenticity must be assessed in its territorial and social context, recognising the multitude of memories and agents that sustain it.

Likewise, the notion of cultural-landscape integrity has incorporated dimensions linked to the environment and community. This discussion is further broadened by the concept of ‘compatibility and continuity’ proposed by Gao et al. [10]. It is now felt that the framework incorporates the interaction between heritage, environment, and the social fabric, particularly highlighting the idea that sustainable conservation requires integration of cultural and natural dynamics. Similarly, Waterton and Smith [29] and Dai et al. [30] emphasise the role of local perceptions and community participation in defining authenticity, over and above unidirectional heritage approaches. Therefore, authenticity is no longer seen as a static attribute, but rather as a process of cultural negotiation which involves memories, emotions, and contemporary practices. This point is also driven home in Fouseki’s [26] recent approach to ‘inclusive authenticity’. It thus becomes apparent that sensibilities and minority perceptions must be incorporated into diagnosis and conservation strategies.

Against this backdrop, this study offers a critical assessment of the conservation of defensive heritage in Castellón. In particular, castles are considered to offer sites which are the intersection of materiality, perception, and historical narrative. In this case, knowledge of physical integrity must go hand-in-hand with understanding symbolic and territorial values, also remembering that authenticity is defined by both material coherence and enduring meaning. The ties between authenticity, integrity, and scenic value in Castellón are analysed, identifying any material and landscape deterioration that disrupts this coherence. A territorial diagnostic model is used to address this, stressing the interdependence of building, environment, and social perception. These three premises are not formulated as hypotheses to be statistically tested but as guiding principles that structure the interpretative framework of this study.

Within this framework, this study addresses a key gap in current heritage management practices, which often prioritise isolated restorations without considering the uneven material survival and territorial fragmentation that characterise extensive defensive systems. By analysing a heterogeneous sample of urban and rural castles, this research seeks to characterise these asymmetries and clarify how material and landscape conditions interact across the territory. From the outset, this research is based on three interrelated premises: authenticity includes material and cultural meaning; loss of visual and territorial integrity is deterioration; and finally, even in its fragmented form, Castellón’s defensive landscape displays authentic relationships which can help guide new management and conservation.

2. Materials and Methods

2.1. Study Area

The province of Castellón, in the northernmost part of the Valencian Community (Spain), offers a paradigmatic territory for the analysis of Mediterranean defensive architecture (Figure 1). Its relief, straddling both the coastline and the mountains of the Iberian system, is reflected in its geographical duality, which has historically conditioned the location and significance of castles. The main role of coastal fortifications (watchtowers, batteries, and walled enclosures) was always to ensure maritime control, while fortifications found further inland were used to survey natural passes and agricultural valleys. This meant that, in turn, the inhabited space was interconnected through visual and symbolic systems [21]. As a result, the territory of Castellón is configured as a continuous fortified landscape, with each enclave forming part of a broader cultural and visual network.

One of the hallmarks of these defensive complexes is their typological diversity. In the mountainous interior, the natural protection offered by topography is an asset for the castles of Culla, Ares del Maestrat, and Morella where rocky surroundings are merged into their construction system. In contrast, the sites of Oropesa, Benicàssim, and Almenara form a coastal surveillance belt, inherited from late medieval strategies. Between these two strips, smaller fortifications and albacaras acted as nodes for communication and territorial control. This typological mosaic is not happenstance, but rather an expression of the territory’s ability to adapt its military architecture to the morphology of the terrain and the historical conditions of the frontier. Viewed as a whole, this offers an ideal opportunity to study the relationship between architectural form, location, and cultural landscape [2,23].

Beyond their formal interest, the castles of Castellón are excellent examples of territorial coherence as they are distributed following a system of reciprocal visibility and spatial control. Viewed through a contemporary lens, this network of historical and perceptual relationships exemplifies landscape integrity, where the value of individual elements is enhanced by their role in the whole [6,14]. These interdependencies prompt a change in thinking that is vital to conservation: defensive heritage is no longer viewed solely as isolated ruins and is instead considered an integrated cultural structure.

For current practitioners, the fragmentary condition of many fortifications results in complexity for interpretations. Throughout Castellón, ruins are a key part of the landscape, and directly shape its perceived authenticity. As Choay [16] and Lowenthal [15] note, material loss does not imply loss of value, but rather it offers potential for new historical and aesthetic perspectives. Castles in ruins, such as Montornés, in Benicassim (Figure 2), illustrate this incomplete authenticity, where eroded material interacts with both the landscape and collective memory [17,18]. Therefore, it becomes essential to find equilibrium between physical conservation and visual impact, always keeping in mind that this relationship between ruin and environment is essential to contemporary analysis.

In recent years, conservation work on castles has cast light on their value in terms of identity, as well as on the challenges of managing them. While some sites have become tourist spots, others are abandoned or undergo modifications which are to the detriment of their appearance. According to Fouseki [26] and Bandarin and van Oers [27], the management of defensive heritage should follow the principles of inclusive authenticity-respecting physical aspects and involving local communities. In the specific case of Castellón, this means moving away from the type of traditional restoration seen in the past, and engaging in a holistic approach to the defensive landscape, viewing conservation, use, and meaning as interconnected.

2.2. Methodology

The methodology proposed combines documentary, territorial and empirical approaches in order to construct a replicable diagnosis of the authenticity and integrity of Castellón’s defensive heritage. Its design is based on three interlinked pillars-bibliographical and documentary review, territorial analysis using open sources and GIS, and field verification-converging in a georeferenced relational database. Following the principles of traceability, transparency and replicability put forward in specialist literature on heritage inventory and diagnosis [31,32] the current structure enables correlations to be established for material, landscape, and perceptual attributes to interpret the framework of a single territory.

2.2.1. Literature and Documentary Review

The first phase required the compilation and systematisation of academic, technical, and regulatory sources. A review was carried out on international literature on authenticity, integrity, and cultural landscape applied to defensive architecture, paying particular attention to the frameworks of ICOMOS [11], UNESCO [33]. UNESCO guidelines emphasise that authenticity depends not only on material fabric but on cultural meaning, historical context and landscape coherence (see Operational Guidelines, paras. 79–86them) and debates on relational authenticity [1,2,7]. Furthermore, a local documentary archive consisting of historical monographs, municipal catalogues, and regional inventories was put together, also featuring information from the General Inventory of Valencian Cultural Heritage in Property of Cultural Interest (PCI) and Property of Local Relevance sections (PLR).

Based on the above, a homogeneous documentary corpus was constructed. Each fortification was identified by a unique code and a set of basic attributes, such as name, type, chronology, bibliographical references, and legal framework. This standardisation process, which is in keeping with current administrative standards, also ensures interoperability of the data with other heritage systems in the future.

2.2.2. Territorial Analysis with Open Data and Gis

The second pillar is territorial and landscape analysis. This was developed in a GIS environment to georeference the individual assets, placing them in their physical, historical, and visual contexts. All spatial data were processed and georeferenced using the ETRS89/UTM zone 30 N coordinate reference system (EPSG:25830). Official layers used include PNOA cartography, CORINE Land Cover, SIOSE, Valencian Cartographic Institute maps, and PCI/PRL boundaries. These layers enabled us to establish a correlation between the location of each fortification and relief, land cover, accessibility, occupation density and protection regime. They were also essential for cross-checking the georeferencing of every site, contrasting official information with field verification, and for generating the attribute table used in the analysis, which is presented in Appendix A.

In view of this, three groups of indicators were defined to translate theoretical concepts into monitorable variables:

(a)

Material authenticity, understood as the visible proportion of original structures, the continuity of historical construction techniques, and the degree of recent replacement or reconstruction of structural elements;

(b)

Territorial integrity, observed in the coherence between the castle and its immediate surroundings, topographical continuity (unbroken or consistent terrain), the relationship with historical routes, and intervisibility (the ability to see and be seen) with other fortifications; and

(c)

Scenic or perceptual value, assessed on the basis of landscape legibility (the ease with which the landscape’s features can be understood), visual coherence between the monument and its surroundings, and the intensity of anthropogenic impacts (human-induced changes), or contemporary barriers.

For reproducibility, each indicator was assessed using explicit criteria: (a) material authenticity: high = >75% original fabric visible and minimal replacement; medium = 40–75% original fabric with partial reconstruction; low = <40% original material and substantial replacement; (b) territorial integrity: high = continuous topography and clear visual/historical links with surroundings; medium = partial continuity with some fragmentation; low = loss of topographical or visual coherence; (c) scenic value: high = landscape highly legible, minimal anthropogenic impact; medium = moderate visual coherence with noticeable alterations; low = strong visual barriers, fragmentation, or high contemporary impacts.

Each indicator was assigned a qualitative rating of high, medium, or low, adapting criteria from ICOMOS [11] and Fairclough [21]. In combination, these values reveal patterns of conservation and landscape coherence using comparative analysis and cartographic visualisation. Spatial density and clustering were assessed through a combined approach, using visual interpretation of distribution patterns together with basic GIS-based metrics such as proximity and spatial dispersion indicators. In a move away from modelling-based interpretations, an interpretative approach was used, favouring a relational reading between architecture and territory without over-quantifying cultural phenomena.

2.2.3. Fieldwork

Fieldwork was conducted intermittently over an eighteen-month period, combining on-site visits for photographic documentation and simple rubrics with a more detailed assessment carried out in the office. A total of 65 castles were surveyed directly in the field, out of the approximately 150 defensive elements included in the sample. The information gathered in all three phases was entered into a georeferenced database, presenting both map and data tables. Each entry includes details such as identification, type, date, conservation state, and a simple assessment of authenticity, integrity, and scenic value. A data analysis was carried out, using thematic maps and comparing variables including type, location, conservation state, authenticity, and integrity.

The analysis does not aim to rank findings by number, but instead to show the changing links between objects, landscape, and meaning. This method reveals the balance between physical conservation and territorial unity, understanding defensive heritage not as simply separate monuments, but as a cultural network.

2.2.4. Integration, Standardisation and Reproducibility

All information is integrated into a georeferenced relational database (geometry + attribute table) with stable keys, and all spatial analysis, mapping procedures and database integration were carried out using QGIS 3.34, ensuring a stable and reproducible software environment. PCI/PRL codes are used where available, and internal identifiers where not. Provenance metadata include source, date of consultation, and version. The field scheme draws on published models for assessing and geographically cataloguing built heritage [31]. It also follows good practices in GIS inventorying in European and Mediterranean contexts, which highlight the need to standardise descriptors before any evaluation phase.

This design deliberately establishes a distinction between the methods and the results. The methodology dictates what is to be reviewed, mapped, or verified, without anticipating diagnoses. At the same time, the system of traceability, verifiability, and transferability to other provinces that is followed results in a very thorough approach, also relying on public sources, regional regulations, and procedures already validated in specialised literature on heritage cataloguing with GIS.

3. Results

The fortifications in the province of Castellón constitute an exceptional concentration of heritage sites in the Valencian region. This distinction comes not from the roughly 150 enclaves listed in provincial records, but from their continuous distribution and varied forms. The defensive system, stretching from coastal plains to inland mountains, forms a network of visual and territorial control linking main historical routes and inhabited valleys. The province preserves all defensive typologies developed between the 10th and 17th centuries, from Andalusian rock castles to walled enclosures and stately fortresses (Figure 3). This variety and dispersion are testament to the persistence of a complex territorial model where landscape, military function, and urban morphology intertwine in a single historical structure.

The distribution reflects a comprehensive occupation: 52% of the elements are in inland mountainous regions (Alt Maestrat, Els Ports, Alto Mijares, and Alto Palancia), 30% are in transition zones, and 18% are on the coast (Figure 4). A comparison of mountains and coast shows a degree of imbalance in the defensive system in Castellón. This confirms that it is not fragmented, as it is clearly a coordinated network of surveillance and control, adapted to the area’s topography and history. Castles in mountainous areas control passages and borders, while urban structures and coastal fortifications support trade and maritime defence. This geographical complementarity further supports the premise that the defensive system operated as a network rather than isolated enclaves, with each fortress strategically positioned for intervisibility and control over resources and roads.

The typological and chronological diversity of the complex is significant. Rock or hilltop castles, sitting on natural spurs and built with masonry, rammed earth, or irregular ashlar that suit the topography, account for 43% of the total. Urban castles and walled enclosures, which make up 28%, are defined by integration into historic centres and the continuity that keeps them as urban landmarks. Castle-palaces or residential castles represent a further 17%, while watchtowers and minor fortifications make up 12%. Chronologically, 57% are of Andalusian origin, 34% are late medieval renovations, and 9% are modern. A combined reading of types and dates shows overlaps between construction phases and uses, with transformation prevailing over replacement. Islamic structures were adapted to feudal needs and, in some cases, used again in modern times. This continuity once again highlights the historical and landscape significance of the fortifications: they are not isolated remains, but material traces of a prolonged territorial process.

The analysis of conservation reveals a precarious equilibrium between permanence and deterioration. 32% of castles are partially in ruins, a further 26% in scattered or advanced ruins, 28% are consolidated, and only 14% have been restored or are in good condition. This distribution mostly shows situations which do not fall under a single category, structures still in need of consolidation, but with enough traces to allow for architectural interpretation. The highest number of examples of consolidated or restored cases can be found in urban castles, making up about one third of the total, while rural or mountain castles are often in ruins. However, this difference cannot be attributed simply to a situation of abandonment versus conservation. It also reflects two ways of thinking as regards persistence. In urban settings, conservation is also at the service of visibility and aids the incorporation of heritage into tourism or identity, whereas in rural settings, ruin represents a direct link to original materials and the historical landscape. This is best summed up in Janssen et al. [34] paradox of use value: intervention preserves form but can weaken material authenticity.

This interpretation is further reinforced by the correlation between construction type and state of conservation. Rock-built and hilltop castles, which represent almost half of the sample, retain a high level of material authenticity (78% of cases) owing to rare interventions and the visibility of original materials. However, only 29% of these castles retain complete or recognisable structures, indicating lower physical integrity. In contrast, urban and palatial castles, often retaining complete forms, achieve medium to high integrity (65%) but are considered to have reduced authenticity due to material substitutions, partial reconstructions, and scenic reconfigurations (Figure 5). This comparison, also noted by Pendlebury [35] in studies on fortified heritage, highlights a common paradox: formal conservation does not always guarantee historical continuity of the property.

When visual integrity, physical integrity and authenticity are considered together, their combined pattern clearly distinguishes between urban from and non-urban defensive contexts. In inhabited (urban) areas, 62% of castles are consolidated or restored, displaying high visual integrity within the city landscape, despite historical contexts modified by modern changes. Conversely, in non-urban areas, 71% of castles are in partial or scattered ruin, but 82% of these retain high visual integrity that is reinforced by the surrounding agricultural or forest environment. Thus, urban castles exemplify preservation and transformation within city limits, while non-urban ruins illustrate coherence with the landscape and enduring authenticity. In both contexts, the monument and landscape merge into a single system of interpretation. The ruin acquires scenic and symbolic value, bearing witness to a balance between architecture and territory throughout history. Material authenticity and contextual integrity together create a unified cultural value, aligning with the concept of ‘silent heritage’ described by Choay [16].

Most recorded interventions are concentrated in regions with the greatest urban dynamism: Plana Alta, Plana Baixa, and Els Ports (Figure 6). However, these regions do not necessarily provide better conservation outcomes than less dynamic areas: as restoration or consolidation in highly visible enclaves tends to prioritise formal stability over material preservation, resulting in heritage sites with strong symbolic value but limited authenticity. In contrast, in inland regions such as Alt Maestrat and Alto Mijares experience intervention tends to be less intense, but a greater coherence is observed between buildings and landscape, even though physical deterioration is still present. This contrast reveals a territorial asymmetry: resources and actions focus on highly visible, tourist regions, while peripheral spaces preserve authenticity and coherence, albeit with little institutional support.

An integrated reading of these variables shows that Castellón’s defensive heritage is shaped not by isolated monuments, but by the tension between form, material, and environment. Urban and rural castles, whether restored or in ruins, share the same process of historical adaptation, one in which physical conservation and material authenticity are engaged in unstable balance. Castellón exemplifies a continuous fortified landscape whose cultural value is largely guaranteed by the link between architecture and territory. The dichotomy between intervention and ruin merges into a shared dynamic of permanence. Here, it is time, not restoration, which mediates meaning. To fully comprehend the defensive system, it becomes necessary to examine the interplay of visibility, coherence, and wear, as these form the basis for reflecting on the reconciliation of conservation, authenticity, and territorial management in contemporary historical landscapes [36,37].

4. Discussion

The results confirm the defensive system of the province of Castellón as a prime example for understanding the interaction between matter, landscape, and memory in Mediterranean heritage contexts. Its territorial distribution, typological diversity, and uneven state of conservation reveal a constant exchange between intervention and permanence. Here, authenticity is less dependent on physical integrity than on the symbolic and territorial continuity of the property. More than half of the defensive constructions analysed (58%) are in partial or scattered ruin, while only 14% are restored or consolidated. However, far from representing a weakness, this asymmetry adds credence to the validity of a heritage model based on the coexistence of material presence and landscape memory.

This interpretation reinforces the three premises underpinning this study, confirming that authenticity depends on material and cultural meaning, that the loss of territorial or visual continuity constitutes a form of deterioration, and that Castellón’s defensive landscape retains coherent relationships despite its fragmentary condition.

A territorial reading of the data reveals a clear pattern. Castles in rural or hard-to-access areas retain high levels of material authenticity, with 70% of cases classed as ‘high’. In contrast, urban enclaves with more widespread levels of intervention show high formal integrity but reduced authenticity. This difference quantifies the tension between use value and memory value, as highlighted by Janssen et al. [34]. Although restoration guarantees visible permanence it can also weaken the material truth of the monument. Despite their deterioration, rural ruins maintain coherence between architecture and territory, reinforcing ‘relational authenticity’ as put forward by Oppio et al. [1] and Jigyasu [7]. Here, authenticity is not simply an attribute of the object, it is a living relationship between matter, environment, and perception.

From a landscape perspective, the results show that visual integrity is the main guarantor of heritage value. In 82% of rural castles, a high degree of scenic coherence is preserved, while among urban castles, this figure drops to 38%. This suggests that, in terms of perception, the loss of landscape can be equated with a loss of integrity. This finding confirms Fairclough’s [8] thesis that the continuity of context and that of the building are equally relevant. The landscape acts not as a passive framework, but as an active component of authenticity. It envelops the symbolic reading of the monument and perpetuates its cultural meaning.

This analysis also reveals a territorial imbalance in the management of defensive heritage. The regions with the most urban and tourist activity (Plana Alta, Plana Baixa, and Els Ports) account for 37% of the interventions documented. However, these interventions do not always yield consistent results from a conservation perspective. In these types of cases, visibility becomes a management criterion, creating heritage sites with high aesthetic impact but limited authenticity. In contrast, inland areas like Alt Maestrat or Alto Mijares receive less institutional attention but preserve original materials and greater topographical continuity, despite the greater fragility of structures. This reversal of values illustrates the dilemma facing heritage: intervention ensures form, while inaction preserves meaning.

Similar situations have been observed in other fortified European landscapes. Notable examples include the Calabrian castles analysed by Della Spina [14] and the Dalmatian systems studied by Milojković et al. [6], where material authenticity is preserved in rural settings. In contrast, in urban or tourist areas the dominant feature is formal integrity. These parallels confirm that Castellón is not an exception, but rather it is part of a broader Mediterranean phenomenon: the growing separation between architectural conservation and territorial coherence. In these settings, ruin does not signal conservation failure. In this case, ruin simply represents an honest form that expresses the historicity of the property and its relationship to time.

The interpretation of these data prompts us to reconsider the very notion of conservation. The castles of Castellón show that heritage sustainability depends more on maintaining meaningful relationships between building, landscape, and community than on restoring the original form. Authenticity is not simply preserved; it is negotiated and experienced. In this sense, the results reinforce interpretations proposed by Bandarin and van Oers [27] and by Fouseki [26]. They call for ‘inclusive authenticity’, an approach in which assessment is not limited to experts or institutions, but includes the local communities who give meaning to the property. In this study, the notion of ‘inclusive authenticity’ is addressed conceptually rather than empirically, as no community interviews were conducted; this represents a methodological limitation that should be considered when interpreting the findings.

From an operational point of view, these findings suggest that heritage management models in the province are in need of careful review. Policies focused on monument restoration or adapting urban castles into museums are insufficient to safeguard overall territorial coherence. Management should move towards integrated territorial conservation strategies. Here, ruins, landscape, and collective memory are viewed as interdependent parts of the same cultural system. This approach, in keeping with recent UNESCO guidelines [33] on heritage sustainability, would enable the creation of coherent networks of fortifications and landscapes, prioritising historical and perceptive interpretation over mere reconstruction.

Future management should prioritise integrated territorial strategies that link fortifications, landscapes and local communities. Rather than relying on isolated restoration projects, heritage planning should reinforce the coherence of the defensive network, safeguard visual and territorial continuity, and promote community involvement in decision-making. This approach would strengthen both authenticity and long-term sustainability across the province.

Ultimately, the marked difference between the 62% of consolidated urban castles and the 71% of rural castles preserved in a ruined state reinforces the value of Castellón as a territorial laboratory. This asymmetry illustrates how defensive landscapes can evolve through divergent material pathways while still sustaining coherent relationships between architecture, landforms and historical perception. Viewed in this light, the case of Castellón provides not only a specific reading of local dynamics but also a transferable interpretative framework for other Mediterranean territories where material preservation is similarly uneven. By foregrounding the interplay between permanence, fragmentation and landscape continuity, the findings offer a grounded basis for approaching defensive heritage in regions whose historical systems likewise depend more on territorial meaning than on the degree of physical reconstruction.

5. Conclusions

This analysis confirms that the heritage value of Castellón’s defensive architecture lies not only in its materiality, but also in the dynamic interplay between form, landscape, and memory. The structural duality revealed by the results shows that rural fortifications, largely in partial or severe ruins, maintain a high degree of authenticity, having preserved original materials, techniques, and locations. In contrast, urban castles, 62% of which have undergone consolidation or restoration work, now display lower levels of authenticity, as interventions have prioritised formal stability over historical continuity. Although these arguments are not truly opposing, they showcase a distinction between two forms of permanence considered complementary: visible persistence in the case of urban castles and silent persistence in the case of rural fortifications.

Integrity emerges as the most decisive criterion for assessing the heritage sustainability of the complex. The high visual coherence recorded in 82% of rural fortifications shows that, in these settings, the landscape acts as an active component of meaning, not a mere scenic backdrop. In contrast, in urban castles where the environment has been lost and visual fragmentation is prevalent, integrity is drastically reduced, barely reaching 38%. Therefore, preserving the defensive heritage of Castellón implies maintaining the legibility of the territory which sustains it, with architecture and landscape forming a single cultural system whose coherence guarantees authenticity.

On a theoretical level, this study has confirmed the three main hypotheses put forward. Firstly, it successfully shows that the castle’s authenticity does not rely solely on its original materials, it also relies on the ongoing cultural meaning linking it to its setting and shared memories. Secondly, it finds that losing territory is a form of heritage loss similar to physical damage, since it breaks the historical story of the place. Thirdly, it shows that the fortified landscape of Castellón, though seemingly fragmented, still offers a real sense of connection. This connection can help guide new forms of management for prioritising the area which focus on protecting the unity of the region and respecting its culture.

In practical terms, the results invite us to rethink conservation policies. The future of this heritage should not focus on isolated big interventions. Instead, it should use connected area management strategies linking networks of fortifications, landscapes, and communities. Seeing the defensive system of Castellón as a cultural whole, not just as scattered ruins or restored sites, would make it possible to conduct better heritage planning. In this plan, real connections lead to action: keeping heritage safe, raising awareness about it on a local scale, and encouraging people’s involvement.

Ultimately, this work shows that authenticity and integrity are not fixed, highlighting the changing nature of relationships between time, form, and place. Their worth lies in how these relationships endure. Furthermore, the fact that everything can continue to tell the story of the landscape as something we all remember together is key. Here, conservation means understanding, or knowing that it is time and place, along with the people living there, which truly hold shared memories. Beyond the specific case of Castellón, this framework provides the theoretical–practical foundations for broader analyses of defensive heritage in other Mediterranean provinces, where similar territorial, landscape, and historical dynamics are present.