After the defeat of 1870 against Prussia, France erected a defense organization of 450 forts and fortified batteries, consisting of 3 curtains of detached forts equipped with artillery guns (“Séré de Rivières” system). Reims region is part of the second line with a belt of 13 fortified structures built and modernized between 1875 and 1892. During World War 1, some of these fortified were integrated into the defense networks and exposed to artillery fire leading with time to different states of preservation. After the conflict, many structures fell into disaffection. Some were assigned to municipalities and decommissioned, turned into stone quarries to provide geomaterials for reconstruction, or even deconstructed in order to take advantage of their land reserve. Other fortifications took advantage from reconversion (museography, wine tourism, storage, reappropriation by associations). The presence of these forts, often unsuspected due to concealment forest and vegetation cover, thus has constituted a parallel vector of territorial dynamism for a century. It is no longer a question of observing the hot and steaming ruins, as they can still appear in the testimonies and archives, it is about analyzing the trajectories of resilience, and remanences acquired by these cooled fortified ruins by the peace. The resulting social uses reflect an appropriation, a perception, which should also be observed and analyzed to consider their current and future trajectory. A spatial analysis using GIS from archival documents (GCTA master plans, aerial photographs), airborne Lidar and field surveys allows a synthetic diagnosis of the multiple trajectories developed by the forts of the Reims belt to be carried out. Their study reveals a significant potential to boost the heritage valuation, through tourist vectors (remembrance tourism, wine tourism), and local associations. Moreover, like the former Champagne battlefields converted into military camps, they represent islands of biodiversity in an openfield landscape dedicated to agro-resources. Their existence thus contributes to the fight against the ecological fragmentation carried by the notion of Green and Blue Tram (TVB). In this sense, they can be classified as natural areas of fauna and flora ecological interest (ZNIEFF), and Natura 2000.