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Ancient Sites in Ohio
Ohio has an embarrassment of ancient riches that most Americans drive past without knowing. The Hopewell culture built Newark Earthworks — the largest geometric earthworks in the world, covering four square miles of central Ohio — between 100-500 AD. Part of the complex is still a functioning golf course; the inner Octagon, precisely aligned to the 18.6-year lunar cycle, is accessible to the public only four days per year. Serpent Mound in Adams County is the world's largest effigy mound — a 1,348-foot coiled serpent curving across a hilltop, visible in full only from the air, sitting inside an ancient meteorite impact crater from 300 million years ago. Ohio's Hopewell culture connected trade routes from the Gulf Coast to the Great Lakes a thousand years before European contact.
These are curated, verified sites — every one accessible to the public on foot. Check current access conditions and hours before visiting. Explore all ancient sites on the Trek4Free map →
Newark Earthworks
The largest set of geometric earthworks in the world — built by the Hopewell culture between 100-500 AD across an astounding 4 square miles of central Ohio. Three preserved sections: the Great Circle (1,200 feet in diameter with an internal moat, always open), the Octagon Earthworks (precisely aligned to the 18.6-year lunar cycle — public access limited to 4 days per year, as it sits within a private golf course), and the Wright Earthworks. UNESCO World Heritage Site. Walking the Great Circle's perimeter makes the scale visceral. Managed by Ohio History Connection at 99 Cooper Ave, Heath, OH.
Serpent Mound
The world's largest effigy mound — a 1,348-foot-long undulating serpent coiled across a plateau above Brush Creek in Adams County, Ohio. Built between 1000 BCE and 1100 AD by Adena or Fort Ancient culture, the serpent curves seven times across the hilltop with its open jaws surrounding an oval form. The entire shape is only comprehensible from the air or the observation tower on site. Remarkably, the mound sits within an ancient meteorite impact crater from 300 million years ago — adding to its otherworldly character. Small admission fee. Managed by Ohio History Connection. Near Peebles, OH.
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