The Bosporus, also known as the Strait of Istanbul, is a narrow, natural strait and an internationally significant waterway located in northwestern Turkey. It forms part of the continental boundary between Europe and Asia, and divides Turkey by separating Anatolia from Thrace. It is the world's narrowest strait used for international navigation. The Bosporus connects the Black Sea with the Sea of Marmara, and, by extension via the Dardanelles, the Aegean and Mediterranean seas.

Two suspension bridges and a cable-stayed bridge cross the Bosphorus. The bridge in the picture is the July 15th Martyrs Bridge, and is 1,074 meters long and was completed in 1973.