The Merchants National Bank building in Grinnell, Iowa, also known as the Jewel Box, was designed by famed architect Louis Sullivan late in his career and built in 1914. Used as a bank for over 80 years, it now serves as the visitors’ center for the town. The building is a National Historic Landmark and part of the Grinnell Historic Commercial District.
Louis Sullivan designed eight “jewel box” banks. There are three in Iowa, two in Ohio, and one each in Wisconsin, Minnesota, and Indiana.