Agricultural and Industrial Heritage as a Resource in Frontier Territories: The Border Between the Regions of Andalusia–Extremadura (Spain) and Alentejo (Portugal)

The border effect on heritage protection, shaped by historical and physical factors, contributes to the formation of socio-territorial systems, particularly in relation to productive landscapes. This study focuses on the Portuguese–Spanish border between Andalusia and Extremadura, a region where inter-regional dynamics mirror international tensions due to the coexistence of differing legislative frameworks. The area is characterized by shared agricultural and ecological systems and fragmented transport networks, which complicate territorial integration. Methodologically, the study involves a selection of seven municipalities based on demographic vulnerability and rural identity, followed by historical and spatial analysis using legal sources, historical dictionaries, and digital platforms for heritage mapping. One of the key components was the identification and documentation of historical mills linked to the Ardilla River and its tributaries, using a combination of official heritage databases and user-generated platforms like Wikiloc and local websites. The twenty-one mills found highlight a significant presence of unprotected yet generally well-preserved mills that exemplify the agricultural and industrial legacy of the region. These assets, often overlooked in formal inventories, underline the potential for cross-border heritage recognition and call for a rethinking of protection strategies through the lens of cultural landscapes and community engagement.