Castle in SW Kos, on top of a rocky outcrop to the south of the settlement of the same name. The castle is first mentioned in 1271 and then again in 1420 by Cristoforo Buondelmonti. An Ottoman raid of 1457 failed to take the castle, where the local inhabitants had taken refuge, because it stood on a defensible location and was well fortified, like the castle at Pyli. In 1461, after successive raids, the Order of St. John was thinking of moving the population of Kos to Rhodes; among the castles which would have been abandoned was the 'Fortezza di Chiffalo'. The castle was severely damaged in the 1493 earthquake and repaired the following year. In 1505, when another Turkish raid was imminent, the order was given to abandon the castle because it was judged inadequate. Ottoman admiral Piri Reis writes about Kefalos (1526): 'The third castle of Kos is called Kifelos. It is situated on the SW side of the island on a hill'. The defences must have included a simple defensive enclosure with vertical walls, of which today only a section survives. To the east of the enclosure stood a smaller polygonal fortification, apparently self-contained. A section of wall 20 metres long oriented NW-SE still survives, which xtends southwards for a further 5 metres. The height of the wall on the outside is remarkable, but is a rather feeble structure. A water cistern still exists within the castle.