Holiday visitors to Kos can hardly miss the huge Castle of the Knights that guards the entrance to Kos harbour. Also called Neratzia Castle, It looks impressive from the outside with massive walls and commanding bastions on all four corners but inside it can be a disappointment with little to see apart from a vast yard littered with broken columns.
The castle was built by the Knights of St John in the 15th century on the site of a former fortress. Work on the castle's inner keep and battlements was begun by a Venetian governor in 1436 and finished by his Genovese successor in 1478. After several attacks by the Turks, the Knights decided to strengthen the fortifications and they built the formidable outer castle walls and towers between 1495 and 1514.
Unfortunately, much of the building stone used for castle construction down the ages was pillaged from other historic sites on Kos, including the noted Asklepeion healing and medical centre on the hills above Kos and from the city's Ancient Agora. Close inspection of many walls will reveal faded carvings and inscriptions that clearly belong elsewhere.
The name Neratzia, often spelt Nerantzia, translates as 'sour oranges' and harks back to when orange trees with particularly bitter fruit once grew all around the castle.
The castle has two precincts. The earlier inner keep has four circular towers at each corner, while the surrounding outer precinct has long battlements, gun ports and massive bastions on all four corners.
The inner and outer precincts are linked by a drawbridge over the former moat, now a palm tree-lined main road the Foinikon. The moat was filled in during Italian occupation of the island in the early 20th century.
Entrance is through the main gate decorated with a Hellenistic frieze of masks and garlands, an immediate example of stone taken from elsewhere, in this case probably a theatre. Above the frieze is the coat of arms of the Grand Master Emery d'Amboise.
Once inside, the visitor can be forgiven for being less than enthusiastic about the surrounding. Don't expect to see much for the entrance fee. Kos Castle is very much a ruin inside with a vast open space littered with broken masonry, few buildings to inspect and little provided in the way of information. A good guidebook or an official tour is pretty much a must.
On the northern side of the castle, separating the precincts is a former warehouse, restored by the Italians, that is now a small museum with sculptures on show and some masonry bearing inscriptions.
The oldest and largest of the bastion towers is found to the south-east, left of the drawbridge. Displayed above the entrance are the blazons of the two Grand Masters of the Order of the Knights Hospitaller; Jean De Lastic, the 36th Grand Master and his successor Jacques de Milly, the 37th.
The polygonal d' Aubusson bastion tower in the north-west commands views over the port while the bastion of Del Carretto to the south-west is similar to the similarly named tower in Rhodes Castle.
The outer castle of Kos was built with massively thick walls partly to defend against repeated attacks by the Turks and partly to take advantage of the developments in artillery cannon through the second half of the 15th century.
Not that it did much good. Damaged by an earthquake in 1495, Kos eventually fell to Turkish invaders in 1523. Fortunately for modern-day visitors, the Turks repaired the castle walls and generally kept the place in good condition. During the 19th century, it was used as the barracks of the Turkish garrison and a home for the Turkish commander of the island.
In 1816 a gunpowder room exploded and destroyed a large part of the castle. Much of what can be seen today is due to the restoration efforts of the Italian Archaeological Department, which removed several Ottoman additions and attempted to restore the castle to its original state.
Visitors today will find they can wander pretty much where they like and views from the battlements are impressive, but steep steps and unguarded sheer drops can make visits with young children a scary experience.
Kos Castle is the biggest of four built on the island of Kos by the Knights of St John. The others are at Pyli, Antimachia and at Kefalos.