Carroll County Iowa (Historic Districts) has 3 places on the National Register of Historic Places including 1 place of Statewide significance. Significant places include Leet, William A., and Frederick Hassler Farmstead District, Holy Guardian Angels Church and Cemetery Historic District, Leet, William A., and Frederick Hassler Farmstead District.
Some of the country's most noteable architects helped create the Carroll County places including Fritz Thoms and Hans Detlefsen. Prominent architectural styles found in Carroll Country are Moderne, Bungalow/Craftsman and Gothic.