Tuesday, May 27There's a photo exhibit on view at the museum under the Gateway Arch now that may make you think about the Arch in a different way. Structures of Our Time: 31 Buildings That Changed Modern Life is a traveling exhibit that showcases buildings that have received the American Institute of Architects' annual 25-Year Award. The award goes to buildings that have been around for a quarter-century or more and influenced their communities, as well as the discipline of architecture itself, in a big way. The photos depict such structures as the stark white skyscraper of NYC's Rockefeller Center, Richard Meier's light-filled Smith House residence (in Darien, Connecticut) and Eero Saarinen's swoop-roofed Dulles International Airport in the District of Columbia. One of Saarinen's other gems, the Arch, is in here, too, along with buildings designed by Frank Lloyd Wright; Skidmore, Owings & Merrill; Louis Kahn; Ludwig Mies van der Rohe; and Charles and Ray Eames. See the free exhibit through August 3. Call 314-655-1700 or visit www.stlouisarch.com for more.