Description: The South Yard behind the Smithsonian Institution Building, the Castle, is bordered on the east by the Arts and Industries Building and west by the Freer Gallery of Art. In the late 19th century, it was the site of small buildings for the Smithsonian Astrophysical Observatory, Taxidermy Studio, National Zoological Park, and Aerodrome Studio. After World War I, a Quonset hut