Bosporus

Strait 27 km/17 mi long, joining the Black Sea with the Sea of Marmara and forming part of the water division between Europe and Asia; its name may be derived from the Greek legend of Io. Istanbul stands on its west side, which is lined with villas and old castles. The Bosporus Bridge (1973), 1,621 m/5,320 ft, links Istanbul and Anatolia (the Asian part of Turkey). In 1988 a second bridge across the straits was opened, linking Asia and Europe. The Bosporus and the Dardanelles, leading to the Mediterranean, have long been of great strategic importance; the strait was refortified by Turkey after the Montreux Convention of 1936.