<P> The first 450 UN employees started working at the Secretariat Building on August 22, 1950 . The United Nations officially moved into the Secretariat Building on January 8, 1951, by which time 3,300 employees occupied the building . At the time, much of the Secretariat Building was still unfinished, and the bulk of the UN's operations still remained at Lake Success . A centralized phone - communications system, was built to facilitate communications within the complex . The UN had completely moved out of its Lake Success headquarters by May . The construction of the General Assembly Building was delayed due to a shortage of limestone for the building, which in turn resulted from a heavy snow at the British limestone quarries that were supplying the building's limestone . The erection of the building's framework began in February 1952 . The Manhattan headquarters was declared complete on October 10, 1952 . The cost of construction was reported to be on budget at $65 million . In 1953, twenty - one nations donated furnishings or offered to decorate the UN headquarters . </P> <P> A new library building for the UN headquarters was proposed in 1952 . The existing UN library, a 6 - story structure formerly owned by the New York City Housing Authority (NYCHA), was too small . The NYCHA building could only hold 170,000 books, whereas the UN wanted to host at least 350,000 to 400,000 books in its library . The new facility was slated to cost $3 million . By 1955, the collection was housed in the Secretariat Building and held 250,000 volumes in "every language of the world", according to The New York Times . The Dag Hammarskjöld Library Building, designed by Harrison and Abramovitz, was officially dedicated in November 1961 . </P> <P> The site of the UN 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, and all were charged in the United States District Court for the Southern District of New York . Benon Sevan later fled the United States to Cyprus, while Aleksandr Yakovlev and Vladimir Kuznetsov decided to stand trial . </P> <P> The currency in use at the United Nations headquarters' businesses is the U.S. dollar . The UN's stamps are issued in denominations of the U.S. dollar . U.S. postal rates must be followed . </P>

Where is the headquarter of the uno situated