Which strait separates the European and Asian sides of Istanbul?

The Bosporus separates the European and Asian sides of Istanbul.

The Bosporus is a narrow natural strait connecting the Black Sea with the Sea of Marmara. Istanbul extends across both of its shores, making it one of the world’s most prominent transcontinental cities. The strait is also commonly called the Istanbul Strait.

Its position has given the waterway exceptional strategic and commercial importance. Ships moving between the Black Sea and the Mediterranean pass through the Bosporus, while bridges, ferries, and tunnels connect the two urban sides of Istanbul. The Fatih Sultan Mehmet Bridge and the 15 July Martyrs Bridge are among its major crossings.

The Bosporus is not the same waterway as the Dardanelles. The Dardanelles lies farther southwest and connects the Sea of Marmara with the Aegean Sea. Together, the Bosporus, Sea of Marmara, and Dardanelles form the Turkish Straits system linking the Black Sea to the Mediterranean.