{"nrhp_refnum":"74001541","name":"Madison Fort","other_names":[],"category":"site","location":{"address":null,"address_restricted":true,"city":"Madison","county":"Lake County","state":"OH","lat":null,"lon":null,"geom_source":null},"listed_date":"1974-07-30","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Prehistoric"],"significance_levels":["state"],"summary":null,"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71989539","wikipedia":null,"wikidata":null},"indexable":false,"url":"https://nationalhistoricalregister.com/ohio/lake-county/madison-fort-74001541/"}