Model of the Quadrangle Viewed from the Southwest, by Unknown, c. 1979, Smithsonian Archives - History Div, A photograph of the model of the Quadrangle, a complex of buildings that contain the Sackler Gallery, National Museum of African Art, S. Dillon Ripley Center, and the South Yard behind the Smithsonian Institution Building, or "Castle," and the Arts and Industries Building. The project of building the Quadrangle was begun in 1979. Opened in 1987, the complex, with three stories underground, is covered by the Enid A. Haupt Garden. This view is from the southwest. Photo 2 of 6..