The aging of the French population is a well- known topic but its effects are more important than is usually thought. The dwelling, the urban living habits, the services and amenities have to be adapted to seniors.The geographer tackles the problem through the relation of elder people to their living territory by using scientific tools provided by environmental psychology, and by referring to medical data.This research work has been made at the professional request of ICADE, one of the leading estate developers in France. The author applies very concrete methods, such as the use of mental maps and GPS trackers, so as to grasp the needs of seniors as accurately as possible. Several experiments have been conducted, at different scales and in different surroundings -Lyon and the Rhône-Alpes region, the Paris region, and also the city of Nice. The third part of the study consists in reflecting on the governance that would be the most efficient to implement the “gerontopôles” (structures associating geriatrics, medical and social care and gerontology).