Neratzia Castle

Neratzia Castle guards the entrance to the harbour of Kos Town, begun by the Knights of St John after they took control of the island in 1314. Major construction started in 1436 and continued in stages until 1514, incorporating stone blocks, columns and inscriptions salvaged from the ancient city of Kos, the Asklepieion and an earlier basilica near the port.

The fortress consists of two concentric rings of walls and was, until the early 20th century, effectively an islet, separated from the town by a seawater moat that was later filled in to create today's Finikon Avenue. Together with the Knights' castle across the strait at Bodrum, Neratzia helped control the narrow sea passage used by ships travelling to and from the Holy Land during the Crusades, and the two fortresses could once signal to one another across the water.

Visitors today can walk the ramparts and inner courtyard for views across the harbour, the old town rooftops and the strait toward Bodrum on a clear day, a fitting reward for anyone chartering a gulet from Kos and setting out to explore the wider Dodecanese.