The Great Serpent Mound is a 1,348-feet-long (411 m), three-feet-high prehistoric effigy mound located in Peebles, Ohio. It was built on what is known as the Serpent Mound crater plateau, running along the Ohio Brush Creek in Adams County, Ohio. The mound is the largest serpent effigy known in the world.

Adams County is a county in the U.S. state of Ohio. As of the 2020 census, the population was 27,477. Its county seat and largest village is West Union. The county is named after John Adams, the second President of the United States.