The Keck Center of the National Academies located at 500 5th Street NW in the Judiciary Square neighborhood of Washington, D.C. Built in 2002 to the designs of architectural firm KCF-SHG, Inc., the postmodern building houses the Marian Koshland Science Museum and National Academy of Sciences headquarters. The building incorporates early 20th century commercial buildings on its E Street side and residential buildings constructed in 1886 on its 5th Street side. These older buildings are designated contributing properties to the Pennsylvania Avenue National Historic Site, established in 1965.
This is one of my older photos I originally uploaded to Wikimedia Commons.