The ocean Bosphorus separates Asian Turkey from East Thrace.
=== Present morphology ===The limits of the Bosporus are defined as the line connecting the lighthouses of Rumeli Feneri and Anadolu Feneri in the north, and between the Ahrkap Feneri and the Kadky nciburnu Feneri in the south ("Fener" is Turkish for lighthouse)
According to ancient Greek mythology, it was said that colossal floating rocks known as the Symplegades, or Clashing Rocks, once guarded both sides of the Bosporus and destroyed any ship that attempted to pass through the strait by crushing them

