Residence of the United States ambassador to the United Nations
The official residence of the United States ambassador to the United Nations, established in 1947, was originally located in a suite of rooms that the U.S. Department of State leased on the 42nd floor of the Waldorf Astoria New York. Described in press reports as "palatial", the ambassadorial residence was the first one to be located in a hotel.
Source: Wikipedia — Residence of the United States ambassador to the United Nations (CC BY-SA 4.0)