The Great Serpent Mound is an ancient earthwork located in Adams County, Ohio. Shaped like a snake devouring an egg, the mound is 410 meters (1,330 feet long) and a meter tall (3 feet). The undulating form of the snake has been tied to astronomical phenomena but it is unclear why it was built or what purposes (if any) it served.
SERPENT MOUND (Ohio) 800 BC-AD 100. 1330 feet in length and 3 feet in height. Representing an unwinding serpent, the mound is sheathed in mystery and controversy. The serpent is thought by most to be about to swallow an egg.