White Tower of Thessaloniki

The White Tower is a cylindrical masonry fortress standing thirty-four meters high on the Thessaloniki waterfront. Built by the Ottomans in the fifteenth century to secure the eastern end of the city's sea walls, the structure replaced an earlier Byzantine tower. It served as a garrison and a notorious prison for centuries, earning the grim name of the Tower of Blood because of the frequent executions that occurred within its walls.