The Peoples Savings Bank is one of Louis Sullivan's famous 'jewel box' bank buildings, designed in 1911 and now listed on the National Register of Historic Places. Sullivan, the father of modern American architecture and the man who first articulated the principle that 'form follows function', spent his later career designing small-town banks across the Midwest while the big commissions went to others.
The building's exterior is covered in Sullivan's characteristically organic ornamental terracotta work — intricate botanical patterns that he designed by hand and that no one has successfully imitated. It still operates as a bank. You can walk in during business hours and see the interior, which retains its original fittings.