United Nations (UN). The site is technically extraterritorial through a treaty agreement with the US government, though it is not a territory governed by the UN. Most local, state, and federal laws still apply within the UN headquarters. Due to the site's extraterritorial status, the headquarters buildings are not New York City designated landmarks, since such a designation falls under the purview of the New York City Landmarks Preservation Commission. The Secretariat Building is directly connected to the Conference Building (housing the Security Council) at its northeast, as well as the Dag Hammarskjöld Library to the south. In addition, it is indirectly connected to the United Nations General Assembly Building to the north, via the Conference Building. West of the Secretariat Building is a circular pool with a decorative fountain in its center, as well as a sculpture executed in 1964 by British artist Barbara Hepworth in memory of Secretary-General Dag Hammarskjöld. The Japanese Peace Bell is just north of the building, and a grove of sycamore trees is planted next to the Secretariat Building. On the western part of the site, along First Avenue, are the flags of the UN, its member states, and its observer states. Outside of the UN headquarters, Robert Moses Playground is directly to the south, and Tudor City and the Ford Foundation Center for Social Justice are to the west. In addition, the Millennium Hilton New York One UN Plaza hotel (within One and Two United Nations Plaza) are to the northwest. The building is physically isolated from other nearby structures, with the nearest New York City Subway station being several blocks away. Because of this, the Secretariat Building appears as a freestanding tower. Historically, the site was part of a cove called Turtle Bay. The cove, located between what is now 45th and 48th Streets, was fed by a stream that ran from the present-day intersection of Second Avenue and 48th Street. A creek from the southern end of modern-day Central Park also drained into Turtle Bay. The first settlement on the site was a tobacco farm built in 1639. The site was developed with residences in the 19th century. Slaughterhouses operated on the eastern side of First Avenue for over a hundred years until the construction of the United Nations headquarters. The UN purchased the site in 1946 under the sole condition that it could never slaughter cattle on the land. Architecture