The littoral urban zones and adjacent coastal marine space are interdependent subsystems, constituting a unified spatial, social and ecological system. Considering these dynamics is crucial for future transformations, aligning with rising expectations for quality of life and environmental accessibility. Investigating coastal settlement evolution and its impact on citizens is pivotal for informed socio-cultural, environmental, and urban planning decisions. For this reason, the chapter examines the city-sea interface, where the urban fringe meets the water fringe, forming a spatial and functional continuum. In particular, the attention is directed towards the ecological and socio-recreational potential of this peculiar coastal space.