{"nrhp_refnum":"100012954","name":"Mast Castle","other_names":["Mast Mansion","Ohio Knights of Pythias Home for the Aged"],"category":"building","location":{"address":"901 West High Street","address_restricted":false,"city":"Springfield","county":"Clark County","state":"OH","lat":null,"lon":null,"geom_source":null},"listed_date":"2026-05-01","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["local"],"summary":null,"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":null,"wikipedia":null,"wikidata":null},"indexable":false,"url":"https://nationalhistoricalregister.com/ohio/clark-county/mast-castle-100012954/"}