Answer: Bosphorus strait
Some extra relevant information:
The Turkish straits that divide Europe from Asia are called the Bosporus and the Dardanelles. These two significant waterways play a crucial role in connecting the Black Sea to the Mediterranean Sea, serving as a natural border between the two continents. The Bosporus strait, located in Istanbul, separates the European and Asian sides of the city, while the Dardanelles strait lies in the southwestern part of Turkey, linking the Aegean Sea to the Sea of Marmara. These straits not only hold great historical and geopolitical importance but also serve as vital trade routes for international shipping.