Hotels near Smithsonian Castle are always on sale with CheapOair! Designed by the architect James Renwick Jr, Smithsonian Castle is situated on then National Mall in Washington DC. This attraction is known for housing the Smithsonian Institution administrative offices and information center. The main highlight of this building is that, it is made up of Seneca red sandstone in the faux Norman style that is the 12 th century combination of the late Romanesque and early Gothic motifs. This historical attraction was designated as a National Historic Landmark in 1965. Find great deals on cheap hotels near Smithsonian Castle, and count on CheapOair for all of your travel booking needs!