||The castle of Chalkis town, Euboea (Karababa fortress) was built by the Turks during the war of 1684 to protect Chalkis from the Venetians who threatened to re-capture the town they had lost to Mohamed II in 1470. It was designed by the Venetian Gerolimo Galoppo and is one of the largest and better preserved medieval castles on the Greek mainland. Ancient spolia which were abundant in situ were used for its construction. The castle is equipped with three ramparts and a tower. The main gate was facing north-east. The only surviving building inside the walls of the castle is a late nineteenth-century church dedicated to Prophetes Elias.