This water strait takes its name from a myth that is about Zeus and his complicated love life. Zeus had a jealous wife named Hera. Bosphorus means cow strait.
Io was a beautiful nun in temple of Hera. Zeus fell in love with Io. Hera was in jealous with Io so Zeus transformed her as a white cow to protect her. Hera found out this event and she had a horse fly attacked to white cow. She left a strait and a sea behind her. That is Istanbul strait.
You can see a white cow on the Bosphorus if you are lucky.