This poster is the fruit of a collaboration between a GIS engineer (Dr Pierre-Olivier Mazagol) who has made a tool to see ancient landscapes of the Gorge de la Loire, a little segment of the Loire River near Saint-Étienne agglomeration, and a geographer (Dr Sarah Réault) specialised in geo-history. Those maps extracts are organised about 2 orientations: - Mapping development between 15th century and current methods for cartography. - Trying to understand how to cross and follow the river (sailing or using banks). All kinds of movements facilitated remotely by reading a map, in peacetime or wartime. That is the reason we choose as title « The gorge de la Loire as a strategic mapped area » for this poster. Its structure focuses of three subjects: - On either side of a current map, extracts are dated from 15th to 19th century. -On left side: The question of the representation of river as an obstacle, possibly political limit. -On right side: crossing and sailing. - Below, the poster give priority to mapping in war or cold war context: maps are from begin of 19th century to middle of 20th century. - This overview ends with new methods of representation, between map and landscape.