Fort Benton - Credit: Wikimedia Commons
Fort Benton, also known as Fort Hill, is a historic American Civil War fortification located near Patterson, Wayne County, Missouri. Its earthen walls measure approximately 100 feet by 100 feet. The fortification supported an encampment of Union troops stationed at Patterson to secure the area against local Confederate guerillas. It was also one of a string of fortifications designed protect Union Missouri from invasion from Confederate Arkansas. (includes 10 photographs) Read more on Wikipedia
Source: en.wikipedia.org