Dyas Hexagonal Barn - Credit: Wikimedia Commons
The Dyas Hexagonal Barn is a historical building located near Bellevue in rural Jackson County, Iowa, United States. Built in 1921, it is a round barn measuring around, with red horizontal siding on a stone foundation, a tin roof, and a central wood stave silo extending through the roof. Despite the common name, the building is actually eight-sided, and is also known as the Dyas Octagonal Barn. Originally the roof was flat or almost flat; it is one of four round barns known to have been built on the same farm. with It has been listed on the National Register of Historic Places since 1986. Read more on Wikipedia
Source: en.wikipedia.org