The Dardanelles is the 61-km-long (38-mi) strait between the Aegean Sea and the Marmara Sea. It is the westernmost section of the waterway that divides Europe from Asia and connects the Mediterranean and Black seas. The width is 1-6 km / 0.75-4 mi and the average depth is 100 m / 328 ft.
The name Dardanelles comes from Dardanus, mythical ancestor of nearby Troy. It was also called the Hellespont in ancient times. According to ancient writers, in mythology, the name derives from Helle who fell from the back of the golden-fleeced ram while passing through the strait on the way to Colchis in the Black Sea.
Despite unpredictable weather and swift surface currents, the Dardanelles has been a strategic water route and an object of conquest throughout history.
Unlike the Bosphorus in Istanbul, there is no bridge today on the Dardanelles. In the 5C BC the Persian King Xerxes built a pontoon bridge which stretched from Abydus to Sestus on his expedition against the Greeks.