(also Manhattan Island) the island that forms the main borough of New York City. It is 14 miles/23.5 kilometres long and 2.3 miles/3.7 kilometres wide, and is between the Hudson River and the East River. It contains many of New York's most famous buildings, including the Empire State Building, and its streets include Broadway and Fifth Avenue. Central Park and Harlem are also in Manhattan. The island is named after a Native American people who once lived there.