The Kastel is a squat 16th-century Venetian fortress at the southern end of Komiža's harbour, built to defend the town from Ottoman raids. The tower now houses the Fishing Museum, which covers the falkusa boat-building tradition, the Adriatic sardine fishery, and the broader maritime culture of Komiža. The collection is modest but genuine — old nets, navigation instruments, models of falkusa boats, photographs of the fishermen who made the Palagruža crossing.
The Kastel building itself is as interesting as the museum inside it. The thick stone walls, the narrow windows, and the position at the water's edge give a strong sense of the vulnerability that shaped Dalmatian coastal towns for centuries. The view from the terrace takes in the full length of Komiža harbour.