The tiny artificial island is in size and located in the East River, just south of Roosevelt Island. It lies midway between the United Nations Headquarters at 42nd Street, in Manhattan to the west, and Gantry Plaza State Park in Long Island City, within Queens to the east. It is legally part of Manhattan and is formally a part of Manhattan Community District 6, which also includes the neighborhoods of Turtle Bay and Murray Hill to the west of U Thant Island.