In the last decades, the Mediterranean region is experiencing economic, social, and spatial changes in its structures. Today, cities are experiencing an increasing number of complex problems regarding internal and external connections, reflecting on the city structural realm. The physical transformation of territories in general and cities in particular are associated with external trends, such
... [Show full abstract] as migration, post-colonization affects, social changes, economic, and political activities. The paper concludes how coastlines act as an interface between internal and external transitions of the Mediterranean region, and highlights those territories as important defensive lines which could embrace the Mediterranean challenges. The attitude of coastlines as a system basis of cities can find a compelling rationale as well as a cohesive meaning of recovering its major role in embracing complex external and internal relations, which result in the formation of a strong and coherent urban system to cope with constant transitions of the region.