The Nebergall "Knoll Crest" Round Barn is located between Davenport and Blue Grass in rural Scott County, Iowa, United States.

[1] Charles W. Nebergall owned Knoll Crest Farm when they contracted with Benton Steele to design and construct a round barn in 1914.

Red vertical board-and-batten siding covers the upper half of the barn that features rectangular windows.

A driveway divides the interior circular arrangement between the horse stalls and the cattle stanchions, which ringed the outer perimeter of the main level.

He wrote articles in publications such as the Kimball's Dairy Farmer of Waterloo, the Breeder's Gazette of Chicago, and the Hoard's Dairyman of Fort Atkinson, Wisconsin as a way to advertise his work.