{"nrhp_refnum":"100002957","name":"Martinez Grammar School Annex","other_names":["Martinez City Hall"],"category":"building","location":{"address":"525 Henrietta St.","address_restricted":false,"city":"Martinez","county":"Contra Costa County","state":"CA","lat":38.01404700000006,"lon":-122.13528699999995,"geom_source":"nps_gis"},"listed_date":"2018-09-14","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":"https://www.wikidata.org/wiki/Q133260159"},"indexable":false,"url":"https://nationalhistoricalregister.com/california/contra-costa-county/martinez-grammar-school-annex-100002957/"}