Which strait separates Europe from Asia at Istanbul?

The Bosporus separates Europe from Asia at Istanbul.

This narrow strait connects the Black Sea with the Sea of Marmara and runs through the centre of Istanbul. It is about 31 kilometres long, with a width ranging from roughly 700 metres to 3.7 kilometres. Istanbul is the only major city built on both sides of the waterway.

The Bosporus has been a crucial route between the Black Sea and the Mediterranean for thousands of years. Its name comes from an ancient Greek term commonly translated as “ox passage.” The strait is governed under the 1936 Montreux Convention, which regulates the passage of military and commercial vessels. It is often confused with the Dardanelles, another Turkish strait farther southwest; the two are separated by the Sea of Marmara.