||The Castle of the Knights of St John, built some time before 1317 on the foundations of older Byzantine fortifications. The walls and towers follow the natural conformation of the cliff. A pentagonal tower on the south side commanded the harbour, the settlement and the road from the south of the island. There was a large round tower on the east facing the sea and two more, one round and the other on a corner, on the northeast side of the enceinte. Today one of the towers at the southwest corner and one to the west survive.