Clay County Iowa (Vacant / Not In Use) has 1 places on the National Register of Historic Places including 1 place of Statewide significance. Significant places include Grand Avenue Historic Commercial District, Grand Avenue Historic Commercial District.
Some of the country's most noteable architects helped create the Clay County places including Geiger Construction Co. and W.C. Barton. Prominent architectural styles found in Clay Country are Classical Revival and Romanesque.