Manhattan (coterminous with New York County) is an island borough within New York City, with a 2007 population of 1,620,867 living in a land area of 22.96 square miles (59.47 km²), it is the most densely populated county in the United States at 70,595 residents per square mile (27,267/km²). It is also the wealthiest county in the United States, with a 2005 personal per capita income above $100,000.00. The borough consists of Manhattan Island, Roosevelt Island, Randalls Island, almost one-tenth of Ellis Island, the above-water portion of Liberty Island, several much smaller islands, and a small section on the mainland of New York State adjacent to the Bronx.
Manhattan is a major commercial, financial, and cultural center of the United States, and to some extent, the world. Most major radio, television, and telecommunications companies in the United States are based here, as well as many news, magazine, book, and other media publishers. Manhattan has many famous landmarks, tourist attractions, museums, and universities. It is also home to the headquarters of the United Nations. Manhattan has the largest central business district in the United States, is the site of both the New York Stock Exchange and NASDAQ, and is the home to the largest number of corporate headquarters in the nation. It is indisputably the center of New York City and the New York metropolitan region, holding the seat of city government, and the largest fraction of employment, business, and recreational activities.
The name Manhattan derives from the word Manna-hata, as written in the 1609 logbook of Robert Juet, an officer on Henry Hudson's yacht Halve Maen (Half Moon). A 1610 map depicts the name Manahata twice, on both the west and east sides of the Mauritius River (later named the Hudson River). The word "Manhattan" has been translated as "island of many hills" from the Lenape language. The Encyclopedia of New York City offers other derivations, including from the Munsee dialect of Lenape: manahachtanienk ("place of general inebriation"), manahatouh ("place where timber is procured for bows and arrows"), or menatay ("island").