I.M. Pei’s East Wing at the National Gallery of Art in Washington, D.C. Completed in 1978, the building has a triangular grid, and is semi underground with pyramidal skylights. The atrium features a giant Caulder mobile. The building itself is a work of modern art, and the bronze plaque identifying it as an I.M. Pei building has been worn from people touching it. Captured March 2, 2011.