The Galata Tower

The Galata Tower (Galata Kulesi in Turkish) — called Christea Turris (the Tower of Christ in Latin) by the Genoese — is a medieval stone tower in the Galata/Karaköy quarter of Istanbul, Turkey, just to the north of the Golden Horn. One of the city's most striking landmarks, it is a high, cone-capped cylinder that dominates the skyline and offers a panoramic vista of Old Istanbul and its environs.
http://en.wikipedia.org/wiki/Galata_Tower