The Ursino Castle of Federico II made built (1239-1250) upon a promontory surrounded by the sea in order to defend the city and the port. It was the residence of the Aragonese royal family and also the residence of the Spanish viceroys. During the XVI century it was walled and during the XVII century it was furter fortified. In 1699 it was surrounded by a stream of lava that totally covered S.Giorgio’s bastion, the moats and a part of the last fortification’s works, taking the structure away from the sea. It was damaged by the earthquakes of 1693 and 1837, thanks to a series of restorations, it became a prison. In 1934 it was restored in order to give it its original Swabian shapes and where it was not possible the Renaissance ones.
The building is a great parallelepiped whose walls are 6,56 feet thick: it is characterized by 4 cylindrical towers (98,43 feet high) on the corners and some semi cylindrical towers (today we can see only two semi cylindrical towers).
Nowadays Ursino castle, the most important swabian castle, is the seat of the Municipal Museum, here you can appreciate the Benedectines’ collections, a part of the “Biscari” collection and the donation of the baron Zappalà-Asmundo.