Throughout the Middle Ages the possession of the Fortress of the feudal lords meant having power over the city and the port. Built around 1000 on Roman remains, of which parts of the curtain in opus reticolatum are still visible, the Fortess resisted, in the twelfth century, the soldiers of Frederick Barbarossa, but was then conquered by the Pisan ships allied to the emperor. In the fifteenth century it was restored and equipped with a square tower, on which a four-sided clock was later fixed; it later became the symbol of the city. Before being destroyed by the bombings of the last war, it was the seat, since 1929, of the Municipality. It is currently used for cultural events and exhibitions.
Nearby you can stop to observe the reconstruction of the Roman Liburna.