The Board of Trade is a 1930 art-deco gem. Inside, manic traders swap futures and options – or, at least, they used to. There aren't many left these days, as most trading is now done by computer versus guys yelling on the trading-pit floor. Outside, check out the giant statue of Ceres, the goddess of agriculture, that tops the building.
The Chicago Architecture Foundation offers tours ($15) of the building's interior two times per month.