Iowa is full of beautiful, historic architecture. One of the crown jewels in Iowa’s architectural landscape is a series of unique and beautiful "Jewel Box" banks, the work of architect Louis Henry Sullivan. Sullivan was born in Boston and was an architect in Chicago from 1875 to the early 1920s. Known as one of America’s most innovative architects, he has been called the "father of skyscrapers" and the "father of modernism." He is also credited with the architectural saying, "form follows function."

The Sullivan "Jewel Box" banks were incredibly well-liked. So well-liked, in fact, that he created many variations of them in the last decade of his life. There are eight "Jewel Box" banks in total, and three of them are right here in Iowa: The Merchants’ National Bank in Grinnell, The People’s Savings Bank in Cedar Rapids and The Henry Adams Building in Algona.

1. Merchants’ National Bank

Merchants’ National Bank is located at 4th Ave. & Broad St. in Grinnell, Iowa. The bank was built in 1914. The bank’s exterior is made up of various shades of brick, from blue-black to golden brown, which gives the building the overall appearance of a reddish-brown hue.

The building adheres to Sullivan’s simple box structure, with incredible detailing on the facade.

Among the building’s most notable features are a series of stained glass windows and a colored glass skylight.

It is also known for its magnificent oversized cartouche surrounding the circular window facing Fourth Street.

The detailing also includes lions or winged versions of lions, a common decorative design in Sullivan’s work.

2. The People’s Savings Bank

The People’s Savings Bank is located at 101 3rd Ave SW in Cedar Rapids, Iowa. The second of the eight "Jewel Box" banks designed by Sullivan, this unique building was built in 1911.

The building is now Popoli Ristorante, an elegant and unique restaurant serving Italian cuisine.

The outside of the building is adorned with terra cotta detailing.

It was constructed of 15 different shades of brick, to give "the effect of an antique Oriental rug," Sullivan said of the building.

The inside contains the original bank vaults, as well as clerestory walls of glass with murals depicting rural life in Iowa.

The murals were done by artist Allen Philbrick.

3. The Henry Adams Building

The Henry Adams Building is located at 123 E State St. in Algona, Iowa. While the building wasn’t designed to be a bank, it is still considered to be one of Sullivan’s "Jewel Box" buildings.

The building was designed and built between 1909 and 1919.

As he did in his other "Jewel Boxes," Sullivan designed the building to include many windows and skylights to allow for maximum natural light in the building.

The building’s simple structure with detailing on the outside near the entrance is typical of Sullivan’s later work.

Want to see more of Iowa’s incredible architecture? There’s No Hotel In The World Quite Like This One In Iowa.