| Round Barn, Washington Township | |
| Coordinates: | 42.5853°N -92.4611°W |
| Area: | less than one acre |
| Built: | 1917 |
| Added: | June 30, 1986 |
| Refnum: | 86001417 |
The Round Barn, Washington Township is a historic building located south of Janesville, Iowa in Black Hawk County, United States. It was built in 1917 as a dairy barn. The building is a true round barn that measures 60feet in diameter.[1] The structure is constructed in clay tile and features an aerator and a two-pitch roof. It was built around a silo with a water tank on top of it. While that is typical of this type of structure, it is the only one known to exist in Iowa.[2] It has been listed on the National Register of Historic Places since 1986.