There were fortifying walls around the city of Sitia from the Byzantine
period. These fortifications were restored by the Genoese and by the Venetians
but were never very strong. In 1539, the pirate Barbarosa conquered the city and
levelled the forts and the town. When the Turks invaded the island the Venetians
destroyed the fort so that it would not fall into the hands of Turks. The ruins
of a Venetian castle are still visible today. A tower of three storeys has survived.
North of the fort there is a little chapel built from the ruins of a Venetian
monastery destroyed by the Turks.
This text is cited Mar 2003 from the Crete TOURnet URL below, which contains images.