Serpent Mound

Serpent Mound is a prehistoric earthwork in southern Ohio, shaped like a giant undulating snake stretching over 1,300 feet along a ridge.

Built by indigenous peoples, likely the Fort Ancient culture, it remains the largest serpent effigy in the world.

The mound's purpose—astronomical alignment, ceremonial site, or territorial marker—is still debated: We visited Serpent Mound during the summer solstice.