The Bosporus separates European Istanbul from Asian Istanbul and links the Black Sea with the Sea of Marmara.
The Bosporus is a narrow natural strait running through Istanbul, Turkey. It is one of the world’s most important waterways because it connects the Black Sea to the Mediterranean through the Sea of Marmara and the Dardanelles.
Istanbul is the world’s most prominent city divided between two continents. The European and Asian districts are connected by several bridges, tunnels and ferry routes, while the strait itself remains a major route for commercial shipping and naval traffic.
The Dardanelles is a different Turkish strait farther southwest. It connects the Sea of Marmara with the Aegean Sea, so ships travelling from the Black Sea toward the Mediterranean pass through both waterways. The Bosporus is also often spelled “Bosphorus” in English.