The date of its construction is approximate, certainly prior to the year 1000.
It was built on the right bank of the river Padenna on the path of the Via Cavour, was provided with a drawbridge over the moat which surrounded the city walls.
On either side of the building rose two round towers which were later replaced by the current square bastions.
Considerable restoration affected the port in 1615, 1774, and in 1857. The last restoration was in 2006