The United Nations is headquartered in New York City, in a complex designed by a board of architects led by Wallace Harrison, and built by the architectural firm Harrison & Abramovitz. 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 17 to 18 acres (6.9 to 7.3 ha) of 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. The term “Turtle Bay” is occasionally used as a metonym for the UN headquarters or for the United Nations as a whole.