New York, New York

The Bellevue Hospital entrance arch, at 27th Street and First Avenue, was built in 1736, and now stands in front of McKim, Mead & White's facade for the 1908-1939 hospital main building. Both have been enclosed inside an atrium built in 2005 by Pei Cobb Freed & Partners. The building is now Bellevue's Ambulatory Care Facility. (Source: AIA Guide to NYC (5th ed.))

By Beyond My Ken (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 4.0-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/4.0-3.0-2.5-2.0-1.0)], via Wikimedia Commons