A spectacular courtyard enclosure of the Patent Office Building in Washington, which was the third federal building erected in Washington DC after the Capitol and the White House. Today it houses both the Smithsonian American Art Museum and the National Portrait Gallery. The glass enclosure over the landmark Greek Revival building’s courtyard provides a central focus for the museums and a gathering point within one of the city’s liveliest and fastest-growing neighbourhoods. It is one of the largest event spaces in Washington.