Headquarters of the United Nations

The Headquarters of the United Nations occupies 17 to 18 acres of grounds in the Turtle Bay neighborhood of Midtown Manhattan in New York City, bordered by First Avenue, 42nd Street, 48th Street and the East River. Completed in 1952, the complex consists of several structures, including the Secretariat, Conference and General Assembly buildings and the Dag Hammarskjold Library, designed by a board of architects led by Wallace Harrison and built by the firm Harrison and Abramovitz, with contributions from Oscar Niemeyer and Le Corbusier. The headquarters holds the seats of the United Nations General Assembly and Security Council, though the International Court of Justice sits separately in The Hague, and although the site is physically in the United States it is under the sole administration of the United Nations and technically extraterritorial through treaty with the United States government.