Castle of the Knights (Neratzia Castle)

The Castle of the Knights, known locally as Neratzia, guards the entrance to the harbour of Kos Town, and it is one of the best preserved medieval fortresses in the Dodecanese. The Knights Hospitaller of Saint John, who ruled Rhodes and several nearby islands from the early fourteenth century, built it in the fourteenth and fifteenth centuries to defend the harbour and the island against Ottoman and pirate attacks. The name Neratzia comes from the Greek word for bitter orange, which once grew here. Kos stayed in the hands of the Knights until the Ottomans took it in 1523, shortly after the fall of Rhodes.

The fortress consists of two enclosures, an inner and an outer ward, linked by a bridge, and the thick walls, corner towers and bastions follow the design of late medieval military architecture. The inner fortress has a square plan with towers at the corners, and the outer wall was added later as a second line of defence against artillery, with a wide moat in between that is now a road with a row of palm trees. Coats of arms of grand masters, among them Pierre d'Aubusson, are carved above gateways and on the walls, and a circular tower carries one of the most prominent displays.

Part of the charm lies in the building's materials. The knights reused stones from the ancient city of Kos, which had been ruined by earthquakes, so you can see column drums, inscribed blocks and fragments of carved marble built into the walls, an unusual sight that blends the classical and the medieval. The effect is of a castle assembled from the debris of earlier centuries.

The setting is also fine. The castle stands on the shore, facing the Aegean Sea toward the nearby Turkish coast, and it gives Kos Town’s waterfront its character, with the old harbour and the line of yachts on one side and the plane trees and ruins of the town centre on the other. The Hippocrates plane tree is just across the road, and the ancient agora is only a short walk away.

Access to the interior has been limited in recent seasons because of restoration work, so check locally whether it is open before planning a visit. Even when it is closed, the exterior can be seen at any time, and the walk around the moat is pleasant. Evening, when the walls are lit and the harbour is calm, is a lovely time for a stroll.