The Castello di Carlo V stands on a rocky promontory above the old port, visible from the sea long before you arrive in Crotone. It is a classic example of Spanish military architecture of the sixteenth century — solid, angular, and built for function rather than display. The castle was constructed after a devastating Ottoman raid and effectively anchored the city's defences for the next two centuries.
Today the castle houses the Civic Museum (Museo Civico), which contains a collection covering Crotone's history from the medieval period to the modern day. The views from the castle walls over the Ionian Sea and the town below are the best in Crotone. On a clear day you can see as far south as the cape at Capo Colonna.