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

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.