The Bosphorus separates the European and Asian parts of Turkey.
The strait runs through Istanbul and connects the Black Sea with the Sea of Marmara. It is one of the world’s most strategically important waterways because ships traveling between the Black Sea and the Mediterranean must pass through the Turkish Straits system. The Bosphorus is also a geographic boundary between Europe and Asia.
Istanbul occupies both sides of the waterway, making it one of the world’s most prominent transcontinental cities. Important landmarks along the strait include the Dolmabahçe Palace, Rumeli Fortress, and the Ortaköy Mosque. Several major bridges and tunnels now link the two shores.
The Bosphorus should not be confused with the Dardanelles, the other major Turkish strait. The Dardanelles connects the Sea of Marmara with the Aegean Sea, while the Bosphorus connects the Black Sea with the Sea of Marmara. Together with the Sea of Marmara, they form the maritime route commonly called the Turkish Straits.