Which city is the principal headquarters of the United Nations?

The principal headquarters of the United Nations is in New York City.

The complex stands on Manhattan's East River, in the Turtle Bay neighborhood. The site was purchased and developed for the United Nations after the organization was founded in 1945. Construction began in 1949, and the complex was formally completed in 1952.

The headquarters includes the General Assembly Building, the Secretariat Building, the Conference Building, and the Dag Hammarskjöld Library. The land is international territory, although New York City surrounds it and the United States provides security and host-country services.

New York is the principal headquarters, but the UN also maintains major offices in Geneva, Vienna, and Nairobi. Geneva hosts important human-rights and humanitarian work, Vienna focuses on areas including drugs and crime, and Nairobi is the headquarters of the UN Environment Programme and UN-Habitat.