Saturday Mills Squared Photo: November 14, 2009

Escher, yes, but also something more sinister. These photos of the U.S. Treasury by Flickr user mindgutter reveal a more playful angle to the work of Robert Mills, America's first great architect. You might know him better as the designer of the Old Patent Office Building (now home to the National Portrait Gallery and the Smithsonian American Art Museum) as well as a couple Washington Monuments.