The current largo Doria corresponds to the entrance to the city for those coming from the area of the sea and the medieval landing place, called “La marina”; the door that opened in the walls in this area took its name. Next to the gate there was a monumental complex unfortunately demolished in 1938, the castrum or fortification built to defend the human and commercial flow that entered the city from the sea side; fortification of the walls dating back at least to the communal age, flanked by two mighty towers and after 1251 became the seat of the Genoese armed garrison. Progressively passed into private hands, in the sixteenth century the castrum belonged to the Cazulini counts, who transformed it into a palace crowned by “aerial galleries” of which we possess a rich documentation; it then became, in the second half of the seventeenth century, the monastery of San Tommaso, established by Gio Maria Oddo for the education of girls. The monastery, abolished by the laws of the Napoleonic age, passed to the Municipality: its church became the Theater, the center of the social life of the city in the nineteenth and early twentieth centuries, and the rest of the complex was used for institutional purposes and housing; until, despite strong opposition, it was unfortunately demolished and was the subject of conspicuous building speculation. The east front of the medieval walls, known from ancient depictions and which can also be assumed to trace the Roman walls here, had been demolished in the 1830s, to allow easier entry into the city for wagons and large carriages.
The ancient city today overlooks the large Piazza del Popolo: it was a trading area since the Middle Ages and there was, just outside the walls, the clapa piscium , the large stone "ciappa" on which the catch that arrived was displayed and offered. from the sea, in a place outside the city for obvious reasons of hygiene, a trade which is also meticulously regulated by the Statutes with frequently updated rules. Next to it, the gardens began, each in an area well identified by the toponymy ( orti de la clapa , orti de la Centa , subsequently orti ad marinam , etc.). The coast line in the Middle Ages, with the landing, was near the current railway line, but the alluvial contribution of the river continued to enlarge the area of the beach. A little further on, since the medieval castrum had now ceased its sighting and defense functions, a decision by the government of the Republic led in 1585 to the construction of another fortification, the “Fortino”, of which the precise project is preserved. In this quadrangular structure typical of the military construction of the end of the 16th century with guards at the corners, a multimedia museum location has been set up today on the historical, archaeological and naturalistic resources of the Gallinaria island and its seabed.