De Kalb County Illinois (Vacant / Not In Use) has 2 places on the National Register of Historic Places including 2 places of Statewide significance. Significant places include Egyptian Theatre and von KleinSmid Mansion.
Some of the country's most noteable architects helped create the De Kalb County places including Elmer F. Behrens. Prominent architectural styles found in De Kalb Country are Art Deco.