Originally incorporated in the ramparts, the White Tower (Lefkós Pírgos) was the main defensive element on the seafront. The Turks rebuilt the tower in the 15C and used it as a prison for the Janissaries, the Sultan's guards who betrayed their master. The guards who revolted against Mahmoud II in 1826 were confined to the tower and massacred. The building became known as the ''Bloody Tower'', an unwelcome title which the Turks decided to suppress by whitewashing the walls and renaming it the White Tower. The tower houses temporary exhibits.