This building is home to the American Art Museum and the National Portrait Gallery. Due to the climatic conditions, in the past the open courtyard of the classicist complex could only be used in spring and fall. Now a canopy designed by Foster and Partners encloses the space. Its three shallow vaults flow one into the other, recalling the customary tri-partite arrangement of the existing building. When the sun is shining, it casts a shadow of the roof structure on the walls and floor and is reflected in the shallow pool.