Modern, Postmodern, contemporary, and other non-classical architectural styles are also seen in the city. The National Museum of African American History and Culture deeply contrasts the stone-based neoclassical buildings on the National Mall with a design that combines modern engineering with heavy inspiration from African art. The interior of the Washington Metro stations and the Hirshhorn Museum and Sculpture Garden are designed with strong influence from the 20th-century Brutalism movement. The Smithsonian Institution Building is built of Seneca red sandstone in the Norman Revival style. The Old Post Office building, located on Pennsylvania Avenue and completed in 1899, was the first building in the city to have a steel frame structure and the first to use electrical wiring in its design.