Manhattan (/mænˈhætən/, /mənˈhætən/) is the most densely populated of the five boroughs of New York City.The borough is coterminous with New York County, founded on November 1, 1683 as an original county of the U.S. state of New York. The borough consists mostly of Manhattan Island, bounded by the East, Hudson, and Harlem Rivers, and also includes several small adjacent islands and Marble Hill, a small neighborhood on the mainland.
Manhattan is often said to be the economic and cultural center of the United States and hosts the United Nations Headquarters. Anchored by Wall Street in the Financial District of Lower Manhattan, New York City has been called both the most economically powerful city and the leading financial center of the world, and Manhattan is home to the world's two largest stock exchanges by total market capitalization: the New York Stock Exchange and NASDAQ. Many multinational media conglomerates are based in the borough. Historically documented to have been purchased by Dutch colonists from Native Americans in 1626, for the equivalent of US$1650, Manhattan real estate has since become among the most expensive in the world, with the value of Manhattan Island, including real estate, estimated to exceed US$4 trillion in 2013.
New York County is the most densely populated county in the United States and is more dense than any individual American city. It is also one of the most densely populated areas in the world, with a census-estimated 2014 population of 1,636,268 living in a land area of 22.83 square miles (59.13 km2), or 71,672 residents per square mile (27,673/km2). On business days, the influx of commuters increases that number to over 3.9 million, or more than 170,000 people per square mile (65,600/km2). Manhattan has the third-largest population of New York City's five boroughs, after Brooklyn and Queens, and is the smallest borough in terms of land area.
Many districts and landmarks in Manhattan have become well known, as New York City receives millions of tourists (a record 56 million in 2014), and Manhattan hosts three of the world's 10 most-visited tourist attractions in 2013: Times Square, Central Park, and Grand Central Terminal. Times Square, iconified as the world's "heart" and its "Crossroads", and as "The Center of the Universe", is the brightly illuminated hub of the Broadway Theater District, one of the world's busiest pedestrian intersections and a major center of the world's entertainment industry. The borough hosts many world-renowned bridges, skyscrapers, and parks. Manhattan's Chinatown incorporates the highest concentration of Chinese people in the Western Hemisphere. The Stonewall Inn in Greenwich Village is considered the birthplace of the modern gay rights movement. The city of New York was founded at the southern tip of Manhattan, and the borough houses New York City Hall, the seat of city government and a National Historic Landmark that is listed on the National Register of Historic Places. Numerous prestigious colleges and universities are located in Manhattan, including the Ivy League Columbia University, New York University, and Rockefeller University, which have been ranked among the top 50 in the world.