Since 2010, our research group has conducted an extensive field campaign on fortified sites from the Spanish Civil War and the Second World War in Italy. In this initial phase, the primary objective was the documentation of the heritage itself through systematic surveys: photographic and digital recordings, cartographic analysis, hand-drawn sketches, and descriptive field notes. These activities aimed to capture the architectural, spatial, and material characteristics of the structures, as well as their integration within mobility systems, infrastructures, and surrounding landscapes.

This long-term empirical engagement provided an in-depth understanding of the defensive architectures' physical integrity, landscape setting, and operational logic. However, the present study, while not neglecting the identification and inventory of this heritage, moves beyond heritage documentation in the strict sense: the focus here is on evaluating interventions of recovery, reuse, and valorization carried out on such sites. The analytical tools described below were therefore designed not to assess the original military assets per se, but to measure the quality and effectiveness of actions taken to conserve, interpret, and reintegrate them into contemporary cultural and social contexts.

In parallel with fieldwork, a targeted literature review was undertaken to identify methodological frameworks that could inform the construction of this evaluation system. Although no comprehensive or universally adopted model exists for twentieth-century military landscapes, relevant guidelines were identified in heritage sectors sharing comparable preservation challenges. Of particular relevance are the ICOMOS/ICOFORT Guidelines on Fortifications and Military Heritage (I.C.O.M.O.S./I.C.O.F.O.R.T., 2021), which define a set of strategic principles relating fortifications to their tactical purpose and landscape setting. Among these, the Mediterranean Wall fortifications in Sardinia-particularly the strongholds and secondary inland lines-align most closely with the Command principle (I.C.O.M.O.S./I.C.O.F.O.R.T., 2021), being designed to monitor extensive 360° territorial sectors and prevent enemy forces from approaching the defended zone. Their camouflaged nature excluded a primary role in deterrence, yet their configuration often incorporated flanking elements to cover blind spots and, in certain cases, depth strategies through successive coastal and inland lines. Direct barrier protection of civilian activities was secondary, as these sites functioned primarily as armed coverage points within a wider defensive network.

A distinctive feature highlighted by the Guidelines is the external functional scope beyond physical boundaries, where the operational range of fortifications-shaped by contemporary technology-extended far into the surrounding landscape, reinforcing their inseparable link with the cultural-territorial context (IPCE (Instituto del Patrimonio Cultural Español, 2024, May 28–30). The document also outlines a broad spectrum of heritage values-architectural and technical, territorial and geographical, cultural, strategic, human and anthropological, memorial and identity-related, educational, historical, social, and economic ((I.C.O.M.O.S./I.C.O.F.O.R.T., 2021), art. 4º)-that frame the significance of such sites. While these values establish a general basis for conservation and intervention, their breadth requires adaptation to the specificities of conflict heritage. The present study builds on these principles, developing targeted criteria to evaluate recovery, reuse, and valorization actions, thus bridging the gap between theoretical guidance and operational assessment.

Further methodological parallels are offered by the Nizhny Tagil Charter on Industrial Heritage (TICCIH (The International Committee for the Conservation of the Industrial Heritage, 2003), whose emphasis on functionalist design, integration of built form with operational apparatus, and embedding in territorial systems is relevant to military heritage. Differences remain in aspects such as camouflage versus visibility, the contested dimension of memory, and reuse patterns often restricted to commemorative purposes.

Given its layered and palimpsestic nature, twentieth-century military heritage intersects with multiple overarching themes in heritage studies, including cultural landscape relationships, conservation challenges, the construction of heritage meaning, collective memory, nationalism, and the socio-political dimensions of cultural identity. These interconnections call for an expanded interpretative framework that situates conflict heritage within the broader discourse on heritage values, power, and cultural narratives (Graham et al., 2016),(Avrami & Mason, 2000). This broader perspective complements the sector-specific frameworks discussed above, providing a conceptual foundation for the evaluative methodology outlined in the following section.

Building on the dual foundation of empirical field observation and theoretical anchoring, the research developed two complementary tools for evaluating valorization strategies. The first is a presence-absence matrix, conceived as a descriptive register indicating whether specific physical and interpretive components-such as trails, signage, rest areas, lighting, or digital media-are present. The second is a qualitative evaluative framework, based on an ordinal four-level scale (Absent -Poor -Good -Excellent), applied across thematic criteria to assess how effectively each element contributes to reuse, interpretive clarity, and cultural integration. While informed by international frameworks (ICOFORT for fortifications, TICCIH for industrial heritage, UNESCO for cultural landscapes), the model represents a context-specific adaptation. Categories such as accessibility, authenticity, integrity, and community engagement were reinterpreted in light of the operational, memorial, and environmental attributes of wartime architectures. Concepts from post-industrial and difficult heritage scholarship were merged with casebased evidence from the field, ensuring methodological robustness and operational relevance.

These indicators ensured that even intangible dimensions-such as interpretive accessibility or community participation-were grounded in observable, replicable evidence rather than subjective impressions. Together, the eight criteria form the analytical backbone of the comparative evaluation. By combining objective indicators with qualitative judgment, and by adapting established heritage principles to the specific challenges of twentieth-century military landscapes, the framework ensures both rigor and innovation.

The multidimensional data gathered during the field campaign were synthesized into a comparative matrix, enabling the identification of recurrent patterns, best practices, and unresolved challenges across the case studies. This matrix also provided the empirical foundation for a systematic comparison of intervention strategies. To ensure the robustness and comparability of the evaluation process, a triangulation of data sources was adopted, including direct field observation, photographic documentation, heritage inventories, urban planning documents, and online platforms. A standardized checklist was applied across all sites to minimize subjective interpretation and maintain consistency in scoring. The result is a methodological framework that combines empirical rigor with interpretive depth, offering a robust tool for the evaluation of adaptive reuse strategies in post-war military landscapes.

The outbreak of the Spanish Civil War (1936-1939)—five years before the construction of the Atlantikwall and following earlier projects such as the Maginot Line—provided a testing ground for advanced military technologies and tactics. During the conflict, the insurgent faction used the island of Mallorca as a strategic base for aerial bombing campaigns against Republican territories, raising fears of amphibious attacks on the mainland. In response, the Spanish Republican government developed a coastal defense plan in 1937 (Figure 6).

This strategy pursued a dual approach (Gil Hernández & Galdón Casanoves, 2007): on the one hand, it involved the installation of coastal artillery and elevated anti-aircraft positions to counter threats from both sea and air; on the other hand, it included the construction of a discontinuous chain of casemates along the coastline to deter amphibious landings. The bunkers—typically spaced approximately 500 meters apart, in line with the effective range of their weaponry—created a defensive mesh intended to maximize territorial control (Figure 6).

The siting of these structures was determined through strategic calculations aimed at maximizing operational coverage while minimizing costs and aerial visibility. Camouflage techniques were employed, such as aerodynamic shaping and the use of locally sourced materials for exterior cladding, which enhanced the integration of the structures into their surroundings. Although a few exceptions appeared in urban zones, the majority of the fortifications were built in sparsely inhabited rural or coastal environments. The implementation of this defensive system was delegated to local authorities, who relied on standardized typologies drawn from military engineering manuals. However, due to the urgency of wartime construction, few original plans have survived. As a result, contemporary reconstructions of this defensive system rely heavily on field studies and fragmented archival documentation.

During the Second World War, the Francoist regime expanded and reused this existing infrastructure in anticipation of a possible Allied invasion. In the 1940s, the regime began restoring earlier structures and commissioned the construction of new, more technically advanced fortifications along the Pyrenees and the Strait of Gibraltar (Atanasio Guisado, 2017). This resulted in a fortified coastal belt extending from Cádiz to Girona, forming what is now known as the Spanish segment of the Mediterranean Wall.

Although more limited in scale than the Atlantic Wall, the Mediterranean Wall adapted as well to the challenges of the Second World War. Italy, in particular, presents a revealing case study. Alongside the reinforcement of internal defense lines—such as the Galla Placidia Line—the Italian authorities launched a campaign to fortify coastal areas starting in May 1943 (Grioni & Carro, 2014). At that time, Sardinia and Sicily were identified as probable targets of Allied amphibious operations, making the rapid development of a coastal defense system a necessity. Italy’s fortification strategy involved the construction of bunkers, batteries, and other defensive facilities located at river mouths, estuaries, ports, and near critical infrastructure such as roads and railways. These interventions often overlapped with or were integrated into pre-existing defensive elements—such as coastal watchtowers from the 15th to 18th centuries and other historical military installations—thereby reinforcing existing surveillance and territorial control capacities.

According to (Grioni & Carro, 2014), more than 1,500 military structures from this period are still preserved in Sardinia alone, many in a relatively good state of conservation. This condition is often attributed to the widespread use of reinforced concrete (Figure 8)—a material chosen for its mechanical strength, durability, and suitability for rapid construction. This stands in contrast to the Spanish Republican period (1936–1939), where wartime material shortages led to a more frequent use of traditional masonry techniques, unlike the later Francoist bunkers (1940–1945), which were indeed built in reinforced concrete. The centralized nature of Italy’s military engineering apparatus—coordinated through the Genio Militare and the Regia Marina—also contributed to the systematic production and preservation of technical drawings and archival records. These documents are now essential for contemporary mapping and cataloging efforts.

The coastal defenses of the Mediterranean Wall followed precise strategic and architectural principles. Most structures were made of reinforced concrete and, when possible, clad with stone or local aggregates to improve camouflage. Morphologically, they adapted to the rugged topography of the coast, minimizing visual impact through chromatic and volumetric integration with the surrounding terrain. Functionally, the bunkers were designed as armored shelters capable of continuously housing personnel. Their internal layout typically included a rear compartment for storage or accommodation and a front area equipped with horizontal embrasures for observation and the deployment of firearms (Figure 8). These features reflect a typological consistency aligned with the defensive doctrines of the time, while also accommodating specific site conditions and logistical constraints.

A fundamental principle common to all these structures was the close correspondence between form and function. Their geometric configurations were dictated by operational needs, giving rise to elementary forms—such as circles and squares—that could be modularly combined to generate more complex spatial solutions. This logic is particularly evident in the family of defensive typologies distributed along the coast of Alicante province (Spain) (Arquitecturas para la defensa de la costa Mediterránea, 2016). Moreover, their construction followed principles of standardization and serial production, reflecting avant-garde architectural trends of the interwar period. These fortifications embody the rationality, functionality, and economic pragmatism characteristic of twentieth-century military design. Although this analysis focuses on Spain and Italy, it is important to acknowledge that the Mediterranean Wall extended across other countries, including France, Croatia, Slovenia, Albania (Stefa et al., 2012), Greece, Libya, and Algeria. In each of these territories, bunkers were constructed at different times but always followed similar defensive logics and compositional principles. Lastly, it is worth noting that the settlement patterns of twentieth-century military architecture often echo those of coastal watchtowers built between the fifteenth and eighteenth centuries to defend the Mare Nostrum. The key distinction lies in their visual approach: whereas earlier towers asserted their presence through large volumes and elemental geometry, many modern fortifications emphasized concealment through landscape camouflage—a tactical necessity to preserve the element of surprise (Figure 9).

The defensive system of the Mediterranean Wall-unlike battlefields marked by epic narratives-belongs more properly to the domain of material culture and military engineering. These ruins, which have rarely witnessed major direct combat, are embedded in the landscape, often camouflaged within its morphology to avoid detection by enemy forces. In this context, an intriguing analogy arises between the soldier defending a position and the tourist exploring a territory. As Diller and Scofidio have pointed out, the English word "travel" originates from travail, denoting labor, hardship, and suffering.

The mission of the soldier intersects with the experience of the tourist: their movements are strikingly similar, and both-albeit in very different ways-leave a visible imprint on the landscape. "Tourism and war seem to represent polar opposites of cultural activity: on the one hand, the paradigm of international agreement (tourism), and on the other, that of discord (war)" (Diller, Scofidio, 1995(Diller & Scofidio, 2011). This reflection becomes especially relevant when considering the location of most bunkers, batteries, and shelters of the Mediterranean Wall, which are often situated in ecologically sensitive areas such as mountains, lagoons, dunes, and coastal zones.

Since the early 21st century, increasing attention has been devoted in Spain to the documentation and cataloguing of these fortifications. Significant studies have addressed the defensive system of the Pyrenees, reinforcement strategies in the Gibraltar area, and wartime infrastructures in Catalonia (Cabezas Sánchez, 2013), as well as the fortifications stretching from the Murcian coast. Particularly noteworthy is the comprehensive inventory of defensive structures along the southern coastline of the Valencian Community ((Arquitecturas para la defensa de la costa Mediterránea, 2016); (Gil-Piqueras et al., 2022)), which has contributed to the inclusion of numerous sites in municipal heritage protection registries.

A similar phenomenon is occurring in Italy. Numerous initiatives have been launched to document and catalogue bunkers along the coast of Sardinia (Sanna, 1999), (Carro & Grioni, 2001), (Rassu, 2013), (Grioni & Carro, 2014), (Verso un Atlante dei sistemi difensivi della Sardegna [Towards an atlas of Sardinia's defensive systems, 2015) Mura, Sanjust, 2016 (Military landscapes: Scenari per il futuro del patrimonio militare [Military landscapes: Scenarios for the future of military heritage, 2018), (Pirinu et al., 2021) (Figure 10), as well as in Calabria (Caniglia, 2023), and in inland regions such as valleys and hills, where defensive positions were often adapted from existing watchtowers. In Emilia-Romagna (Mariotti et al., 2018), some bunkers have been reappropriated by local communities and successfully integrated into the contemporary urban fabric.

The creation of detailed location maps, metric and graphic documentation of these structures, and the comparative analysis of their architectural and spatial characteristics have laid the groundwork for future academic research. This has significantly advanced our understanding of the distributed defensive systems that line the Mediterranean coast. However, beyond documentation, the key challenge remains the implementation of concrete interventions aimed at the recovery and reuse of this often neglected heritage, much of which is located in areas of exceptional environmental and landscape value (Figure 11).

The four case studies selected for this research exemplify the proposed multidimensional and diachronic territorial methodology. They include two sites in Spain—the Military Park of Cabo de Santa Pola and the historical-environmental area of Clot de Galvany in Elche—and two in Sardinia, Italy: The Archaeological and Naturalistic Memory Park of Poggio dei Pini in Capoterra, and the fortified zones within the Molentargius Natural Park in Cagliari. Each site offers a distinct configuration in terms of territorial scale, governance, and reuse strategies, providing a valuable framework for comparing how twentieth-century military heritage is reinterpreted and integrated into contemporary park environments. A key visual component of this section is Figure 13, which presents a cartographic comparison for each site. On the left, aerial imagery and orthophotos—produced through systematic field surveys and GIS mapping—document the distribution of wartime infrastructure such as bunkers and defensive nodes. On the right, official maps and interpretive graphics—issued by local authorities, civic associations, or displayed on-site—illustrate the spatial narratives through which these elements are framed, included, or neglected. This juxtaposition highlights discrepancies between the material reality of the heritage and its institutional representation. It also clarifies how each park conceptualizes the relationship between military remnants and other landscape components—such as ecological systems, pedestrian networks, and urban edges. As a preliminary analytical tool, Figure 13 provides both a spatial and semiotic entry point for evaluating the degree of visibility, coherence, and integration of military heritage across diverse contexts.

The following discussion builds upon this synthesis, examining how each site approaches the recovery, reuse, and activation of military structures—not merely as vestiges of the past, but as dynamic components within ecological, experiential, and educational narratives that shape the identity of the park. In this sense, the comparative figure serves as a heuristic device, revealing both the potential and the shortcomings of current valorisation practices. From the elevated ridge of Cabo de Santa Pola to the wetlands of Clot de Galvany, from the wooded inland slopes of Poggio dei Pini to the saline plains of Molentargius, these sites embody distinct topographies and degrees of integration of military remains into public memory and landscape design.

While this overview offers a cross-sectional reading of territorial and representational dynamics, the following subsections present a detailed site-by-site analysis. Here, the proposed evaluation method is applied to assess not only the conservation status and legibility of the military components, but also the strengths, limitations, and contradictions of the reuse strategies adopted. This structured comparison aims to identify recurring patterns, critical issues, and emerging opportunities for more coherent approaches to integrating military heritage into the landscape.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors/individuals."

Not applicable.

The author(s) declare that there is no competing interest.