The Castello Maniace stands at the southern tip of Ortigia on a rocky promontory where the sea crashes on three sides. The castle was built by the Norman emperor Frederick II in the 13th century on the site of an earlier Byzantine fortification, and is a fine example of the austere, geometric military architecture that Frederick favoured across his southern Italian domains. The exterior, with its massive square tower and twin corbelled arches, is more impressive than the interior, which has been stripped over centuries.
The castle gives its name to the narrow alley of the same name that runs from the Piazza del Duomo down to the sea — a route worth walking in its own right for the old palaces and the sense of arriving at the very end of the island. The terrace around the castle base offers views south across the open sea and back north toward the city, and is uncrowded compared to the Fountain of Arethusa.