{"nrhp_refnum":"66000625","name":"Fort Ancient","other_names":["Fort Ancient State Memorial"],"category":"site","location":{"address":"OH 350","address_restricted":false,"city":"Lebanon","county":"Warren County","state":"OH","lat":39.407047837500045,"lon":-84.09220377763135,"geom_source":"nps_gis"},"listed_date":"1966-10-15","is_nhl":true,"nhl_designated_date":"1964-07-19","areas_of_significance":["Prehistoric"],"significance_levels":["national"],"summary":{"what_it_is":"Fort Ancient is a prehistoric earthwork enclosure of about 100 acres on a bluff above the Little Miami River southeast of Lebanon, Warren County, Ohio, built by the Hopewell people and later occupied by the Fort Ancient culture.","why_significant":"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.","narrative":"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.","period_of_significance":"300 B.C. to 250 A.D. approximately, 1200-1600 A.D.","architect_builder":"Hopewell people (prehistoric builders)","architectural_style":null,"criteria":[],"status_note":"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.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:10.333151-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/66000625_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/66000625/b19ddb0744-800.webp","url_1600":"https://nationalhistoricalregister.com/media/66000625/b19ddb0744-1600.webp","licence":"CC BY-SA 3.0","author":"Rdikeman at English Wikipedia","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Fort_ancient_main_trail_2006.jpg\" rel=\"noopener\">Rdikeman at English Wikipedia</a>, <a href=\"http://creativecommons.org/licenses/by-sa/3.0/\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Fort_ancient_main_trail_2006.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71986555","wikipedia":"https://en.wikipedia.org/wiki/Fort_Ancient_(Lebanon,_Ohio)","wikidata":"https://www.wikidata.org/wiki/Q5470727"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/warren-county/fort-ancient-66000625/"}