Some sources suggest that the castle of Gaeta was built in the 6th century, during the war against the Goths. Safer sources date the construction back to the 12th century, when Frederick II of Swabia, to defend their territory during the war between the Guelphs and the Ghibellines, came to Gaeta to give start to the construction of some fortifications, including the castle.
Today, the building is divided in two parts: the oldest part dating back to the Angevin period and the more modern part built by Charles V of Hapsburg. In the past, it was also the seat of the military prison. Today, the two buildings of the castle are occupied in part by the Caserma Mazzini of the Guardia di Finanza and partly entrusted to the University of Cassino, that wants to establish in its spaces the faculty of seafaring disciplines.
