ISTANBUL BOGAZI OR BOGAZICI (BOSPHORUS)
The Bosphorus is a narrow, navigable strait between Europe and Asia connecting the Black Sea (Pontus Euxinus) to the Marmara Sea (Propontis).
It is about 31 km / 20 mi long and varies between 1 and 2.5 km / 0.5 and 1.5 mi wide. The narrowest point is 700 m / 2,300 ft between the fortresses of Rumeli and Anadolu. Swift currents make navigation difficult. The average depth is 50 m / 164 ft. In the Bosphorus there are two currents; one on the surface from the Black Sea towards the Marmara Sea and one below the surface in the opposite direction. The Black Sea is 24 cm / 9.5 in higher than the Marmara and this causes the current on the surface. The other current is because of the changes of salt rates in the two seas.
Along both shores are many attractions including ancient ruins, picturesque villages and forested areas. Near the southern end is the Golden Horn, the harbor of Istanbul, one of the most commodious natural harbors in the world.
In ancient and medieval times almost all commerce between the Mediterranean and Black seas was routed through the strait. It is still an important artery of international trade. An average number of 38,000 ships pass through the Bosphorus annually.
The name Bosphorus means “ford of the calf” in ancient Greek and is derived from the myth of the maiden Io.
In mythology, Io is seduced by Zeus and changed into a milk-white heifer to protect her from the jealousy of Hera. When Hera asked Zeus for the heifer, Zeus complied and Hera employed the hundred-eyed Argus to guard Io. After Argus was slain by Hermes at the behest of Zeus, Hera tormented Io with a gadfly, driving her from land to land crossing the strait between Asia and Europe and giving its name, Bosphorus.