United Nations Headquarters

The headquarters of the United Nations is a complex in New York City. The complex has served as the official headquarters of the United Nations since its completion in 1952. It is located in the Turtle Bay neighborhood of Manhattan, on spacious grounds overlooking the East River. Its borders are First Avenue on the west, East 42nd Street to the south, East 48th Street on the north and the East River to the east. Turtle Bay is occasionally used as a metonym for the U.N. headquarters or for the U.N. as a whole.

The United Nations has three additional, subsidiary, regional headquarters or headquarter districts. These are located in Geneva (Switzerland), Vienna (Austria), and Nairobi (Kenya). These adjunct offices help represent UN interests, facilitate diplomatic activities, and enjoy certain extraterritorial privileges, but only the main headquarters in New York contains the seats of the principal organs of the UN, including the General Assembly and Security Council. All 15 of the United Nations' specialized agencies are located outside New York at these other headquarters or in other cities.

Though it is in New York City, and part of the United States, the land used by the United Nations Headquarters is under the administration of the United Nations, while also being subject to most local, state, and federal laws. For award purposes, Amateur radio operators consider it a separate "entity", and for communications the UN has its own internationally recognized ITU prefix, 4U.
The United Nations Headquarters complex was constructed in New York City in 1949-1950 beside the East River, on 17 acres (69,000 sq.m) of land purchased from the foremost New York real estate developer of the time, William Zeckendorf. Nelson Rockefeller arranged this purchase, after an initial offer to locate it on the Rockefeller family estate of Kykuit was rejected as being too isolated from Manhattan. The $8.5 million purchase was then funded by his father, John D. Rockefeller, Jr., who donated it to the City. The lead architect for the building was the real estate firm of Wallace Harrison, the personal architectural adviser for the Rockefeller family.

The site of the United Nations Headquarters has extraterritoriality status. This affects some law enforcement where UN rules override the laws of New York City, but it does not give immunity to those who commit crimes there. In addition, the United Nations Headquarters remains under the jurisdiction and laws of the United States, although a few members of the UN staff have diplomatic immunity and so cannot be prosecuted by local courts unless the diplomatic immunity is waived by the Secretary-General. In 2005, Secretary-General Kofi Annan waived the immunity of Benon Sevan, Aleksandr Yakovlev, and Vladimir Kuznetsov in relation to the Oil-for-Food Programme. All have been charged in the U.S. Federal Court of New York, except for Kofi Annan's own son, who was also implicated in the scandal. Benon Sevan later fled the U.S. to Cyprus, while Aleksandr Yakovlev and Vladimir Kuznetsov decided to stand trial.

The complex has a street address of United Nations Headquarters, New York, NY 10017, USA. For security reasons, all mail sent to this address is sterilized, so items that may be degraded should be sent by courier. The United Nations Postal Administration issues stamps, which must be used on stamped mail sent from the building. Journalists, when reporting from the complex, often use "United Nations" rather than "New York" as the identification of their location in recognition of the extraterritoriality status.

source and more information: wikipedia