{"nrhp_refnum":"87002028","name":"Sankaty Head Light","other_names":[],"category":"structure","location":{"address":"Sankaty Head, Nantucket Island","address_restricted":false,"city":"Nantucket","county":"Nantucket County","state":"MA","lat":41.28163064000006,"lon":-69.96748020056822,"geom_source":"nps_gis"},"listed_date":"1987-10-15","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation","Maritime History"],"significance_levels":["state"],"summary":{"what_it_is":"Sankaty Head Light is a brick lighthouse tower and station on a clifftop about one mile north of Siasconset on Nantucket Island, Massachusetts. The tower was built in 1849-50, and the oil house dates to 1887.","why_significant":"The nomination argues the light has integrity of location, design, setting, materials and workmanship, and important associations with the development of aids to navigation in Massachusetts. Its Fresnel lens, one of the first installed in a U.S. lighthouse, made the light so brilliant that fishermen called it the \"blazing star.\" It is rated significant at the state level under criteria A and C.","narrative":"Sankaty Head Light is a brick lighthouse on a cliff about 160 feet above the Atlantic, roughly a mile north of Siasconset on Nantucket. Benjamin F. Isherwoode directed construction of the 60-foot tower in 1849 at a cost of $10,333, with materials brought in by ship. It was first lit in February 1850. Its Fresnel lens, bought in France, produced a light so bright that fishermen called it the \"blazing star,\" and it warned mariners away from the Southern Shoals. A balcony and lantern added later raised the tower to 70 feet, and an oil house was built in 1887. The lens was electrified in 1933 and the lamp and lens rooms were rebuilt in aluminum in 1970. The station also holds two 1960 ranch-style houses and a helicopter pad, which do not contribute to its historic character. The light was listed for its role in the development of navigation aids in Massachusetts and for its architecture and early Fresnel lens.","period_of_significance":null,"architect_builder":"Benjamin F. Isherwoode (Isherwood) directed construction of the tower","architectural_style":null,"criteria":["A","C"],"status_note":"Listed as an unmanned, active aid to navigation owned by the U.S. Coast Guard. A later letter describes the 90-foot bluff as rapidly eroding and proposes moving the tower inland.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:13:01.328265-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/41/7923/63792341/content/electronic-records/rg-079/NPS_MA/87002028.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/87002028/87e1030601-800.webp","url_1600":"https://nationalhistoricalregister.com/media/87002028/87e1030601-1600.webp","licence":"CC BY-SA 3.0","author":"Denimadept","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Sankaty_Light,_2009-04-07.jpg\" rel=\"noopener\">Denimadept</a>, <a href=\"https://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:Sankaty_Light,_2009-04-07.jpg"},"district":{"nrhp_refnum":"66000772","name":"Nantucket Historic District","url":"https://nationalhistoricalregister.com/districts/massachusetts/nantucket-historic-district-66000772/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63792341","wikipedia":"https://en.wikipedia.org/wiki/Sankaty_Head_Light","wikidata":"https://www.wikidata.org/wiki/Q7418689"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/nantucket-county/sankaty-head-light-87002028/"}