Which strait separates the European and Asian parts of Turkey?

The Bosphorus separates the European and Asian parts of Turkey.

The Bosphorus is a narrow natural strait connecting the Black Sea with the Sea of Marmara. It runs through Istanbul, making the city one of the few major urban centers situated on two continents. The European side lies to the west, while the Asian side lies to the east.

The waterway is approximately 31 kilometres long, though its width varies considerably. Strong currents and a winding course have made navigation challenging throughout history. Modern Istanbul is linked across it by several bridges, tunnels, and ferry routes, and the strait remains an important international shipping passage.

The Bosphorus is sometimes confused with the Dardanelles, another Turkish strait farther southwest. The Dardanelles connects the Sea of Marmara with the Aegean Sea, while the Bosphorus connects the Sea of Marmara with the Black Sea. Together with the Sea of Marmara, these waterways form the maritime route between the Black Sea and the Mediterranean.