Often located on the water’s edge, “spontaneous urban beaches” are urban spaces where urbanites adopt beach behaviors without the space having been designed for that purpose. Such public spaces redefine the ordinary urban life and allows new sensitive experiences and new forms of body presence in the public urban space. They highlight the emergence of a new urbanity made of idleness, immobility and exposure. The aim of our research is to identify the spatio-temporal, climatic, sensitive, cultural, social and political conditions for the appearance of a beach situation that modifies the ambiance and the experience of the contemporary urban environment.