Heraklion, as a typical Mediterranean port-city, is characterized by all the pathologies resulting from the strict separation of city and port, with the waterfront area distinguished by spatial discontinuities and urban voids. This project deals with the urban activation of the city waterfront. Aiming to overcome the "abandoned threshold", the proposal focuses on the "port-city interfaces", where through the redevelopment of public space and the design of reference spaces and buildings, the creation of a new urban centrality is attempted, composing the new urban landscape, the "fluid city".