The Bosphorus (also spelled Bosporus; Turkish: Boğaziçi or İstanbul Boğazı, "Istanbul Strait"), about 30 kilometers (19 mi) long and only 700 meters (2,300 ft) wide, connects the Sea of Marmara with the Black Sea in the north. It runs through the city of Istanbul, making it a city located on two continents. It is crossed by three suspension bridges (the Bosphorus Bridge, the Fatih Sultan Mehmet Bridge and the Yavuz Sultan Selim Bridge), and two underwater tunnels (the Marmaray rail tunnel and the Eurasia road tunnel).