In this chapter, the geo-spatial approach developed for the city-sea interface is applied. In particular, the analysis of the main features of the urban coasts of Naples and Marseille refers to the maritime city edge portion of the two cities, that is, the area between the coastline and the first transit road parallel to the coast. This choice is supported by the presence of intense pressures in this area, from the point of view of the terrestrial sphere, directly influencing the water mirror and the functions it could take on, but also the innermost coastal areas of the city-sea interface.