The castle that crowns the promontory was built by the Genoese in the 16th century on the foundations of an earlier medieval fortification. It is a compact military structure — thick walls, square towers, no ornamental pretensions — built to control the narrow entrance to the Gulf of La Spezia and to protect the village from seaborne attack. The Doria family, Genoa's most powerful maritime dynasty, held it for centuries.
The castle is reached by climbing a steep stairway from Via Capellini through the old Genoese gate and up through the remaining sections of the medieval walls. The views from the battlements are the widest available in the village: south to the open sea and the Tino and Tinetto islets, north along the gulf toward La Spezia, and west to the bulk of Palmaria island lying just offshore. In summer it opens for temporary exhibitions; check locally for current hours and admission.