The Harnsberger Octagonal Barn, also known the Mt. Meridian Octagonal Barn, is located near Grottoes, Virginia. Built about 1867, the barn is possibly the only example of such a barn in Virginia, as the building style was more popular in the expanding midwestern United States in the immediate post-American Civil War era than in economically-depressed Virginia. The octagonal style was popularized in 1853 by A Home For All, or the Gravel Wall and Octagon Mode of Building by Orson Squire Fowler. The barn was placed on the National Register of Historic Places on July 8, 1982.