The entire city is surrounded by 9 Km of walls, built in the 1500's. One can only go around them by bicycle or on foot, either on the embankment or below in the moat. Bastions, towers, battlements, gates and passages unfold one after another, evidence of the diverse defensive techniques elaborated over the course of centuries.They are in the Unesco list of the world heritage
Yes you are right. The fortified walls of Malta are of the same era as the Ferrara ones. I have recently been to Rhodes, where also there are impressive wall and fortresses. The Mediterranean has a history of fighting and defending itself @sangwann