Fort Ancient
Also known as: Fort Ancient State Memorial
Why it's listed
Fort Ancient is a large earthwork enclosure on a bluff 270 feet above the Little Miami River in Warren County, Ohio. Earth and limestone walls, 4 to 23 feet high, follow the hilltop contour and surround roughly 100 acres, with about 70 gateways. Inside are burial mounds, stone pavements and stone circles, divided among North, Middle and South Forts. Early observers thought it a fortification, but later excavations showed that the Hopewell built it between about 300 B.C. and 250 A.D., probably for ceremonial use. Hopewell artifacts such as effigy pipes, mica and copper ornaments were found in depressions within the walls. Centuries later, people of the Fort Ancient culture settled in South Fort and at nearby Anderson Village between 1200 and 1600 A.D. The state began buying land in 1891, and Civilian Conservation Corps crews restored many earthworks in 1933-35. The site is considered among the finest Hopewell earthworks and a key source on Hopewell village life.
Significance in brief: The nomination calls it the outstanding enclosure of its kind in the country and probably the finest Hopewell hilltop earthwork. It was likely a ceremonial center, with burial mounds, stone pavements and parallel walls. Excavations of the Hopewell village nearby and of later Fort Ancient villages add to knowledge of both cultures.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 66000625, listed October 15, 1966. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | OH 350, Lebanon |
|---|---|
| County | Warren County |
| Listed | October 15, 1966 |
| Reference number | 66000625 |
| Resource type | Site |
| Period of significance | 300 B.C. to 250 A.D. approximately, 1200-1600 A.D. |
| Architect / builder | Hopewell people (prehistoric builders) |
| Areas of significance | Prehistoric |
| Level of significance | National |
| National Historic Landmark | Yes, designated July 19, 1964 |
| Status (as stated in the nomination) | Condition is stated as good, though altered by erosion, cultivation and early excavations; most of the site is state-owned and operated as a public park with a museum. |
| Acreage | 850 |
| Coordinates | 39.40705, -84.09220 (NPS GIS) |
What listing means for this property
Sites (archaeological sites, battlefields, landscapes) are often listed with a restricted address to protect them from looting or disturbance. Listing is honorary for private owners; federal undertakings on or near the site go through Section 106 review, and state laws may protect burials and artefacts regardless of listing.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 66000625.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5470727
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.