The Dardanelles connects the Sea of Marmara to the Aegean Sea and forms part of the Turkish Straits. This narrow waterway lies in northwestern Turkey, between the Gallipoli Peninsula in Europe and the Troad region of Asia.
The Dardanelles is about 61 kilometres long and varies considerably in width. Through the Sea of Marmara and the Bosporus, it creates a maritime route between the Black Sea and the Mediterranean. That geography has made it one of the world’s most strategically important waterways for trade and naval movement.
In classical antiquity, the strait was called the Hellespont. Its most famous modern historical episode was the 1915 Allied campaign at Gallipoli during World War I, when control of the waterway was a major military objective.
The Bosporus is the usual mix-up: it connects the Black Sea to the Sea of Marmara, while the Dardanelles continues from Marmara toward the Aegean. The two waterways, with the Sea of Marmara between them, together make up the Turkish Straits.