New Post Office Building, Twelfth Street and Pennsylvania Avenue, Washington, District of Columbia, DC

Significance: Located at 12th Street and Pennsylvania Avenue, the Ariel Rios Federal Building, also known as the new Post Office, was designed by William Adams Delano and William T. Aldrich and constructed between 1931-1935. Inspired by the Place Vendome in Paris, the Ario Rios Federal Building was intended to be a central feature of the Federal Triangle. The central section of the tri-unit building is comprised of two huge, back to back, semi-circular units with side wings. The hemicycle formed by the building's curve was to be mirrored by a similarly curved façade built across 12th Street on the site of the Old Post Office Building. However, preservation efforts in the 1970's saved the Old Post Office from demolition and the second half of the grand plaza was never finished as designed. The Ariel Rios Federal Building's seven-story spiral marble staircase is a prominent element of the interior. A chandelier hangs in the center of the staircase and has exposed bulbs to illuminate each floor. It terminates in a dramatic chrome and brass globe.
Survey number: HABS DC-814