Halfway between Indianapolis and Louisville, a red-steel arch rises over I-65, breaking the infinite loop of cornfields and truck stops – the first sign of something amid all this nothing. Columbus, a city of 44,000, is the unlikely home to more than 60 design treasures, buildings designed by I.M. Pei, Richard Meier, Robert Venturi, and other world-class architects. The bounty is a gift of J. Irwin Miller, who helped turn the local Cummins Engine Company into a postwar manufacturing giant. Since 1954, the Cummins Foundation has doled out $22 million to fund high-design public works. The results dot nearly every downtown corner. A few blocks from City Hall, whose courtyard is covered by cantilevered beams, is a giant, multicolored installation resembling a pipe organ. Nearby sits Pei's public library with its coffered concrete ceiling. But Columbus' crown jewel may be Miller's home, a modernist wet dream designed by Eero Saarinen, with a sunken living room and skylights illuminating glass and stone walls. It's the kind of place you'd expect to find anywhere but here.

Getting there: From Indianapolis, drive to Columbus on I-65. The Columbus Visitor's Center offers two-hour guided tours of the city's architecture Tuesday through Friday.