{"nrhp_refnum":"04000189","name":"Nix's Mate Daybeacon","other_names":["Nix's Mate channel marker or day marker"],"category":"structure","location":{"address":"Nubble Channel, The Narrows, Boston Harbor","address_restricted":false,"city":"Boston","county":"Suffolk County","state":"MA","lat":42.33230821600006,"lon":-70.94440608399998,"geom_source":"nps_gis"},"listed_date":"2004-03-18","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Maritime History"],"significance_levels":["local"],"summary":{"what_it_is":"A federal aid to navigation at Nix's Mate, a former island reduced to a rocky shoal near the outer limits of Boston Harbor, Massachusetts. It is a wooden octagonal pyramid clad in concrete on a granite block base, with base work dating to 1805 and 1834 and the pyramid rebuilt after an 1841 fire.","why_significant":"The nomination argues significance under Criterion A for its link to the development of navigational aids in Boston Harbor, led by the Boston Marine Society, the Commonwealth and later the federal government. Under Criterion C it is a rare surviving permanent, unlit day marker, with a distinctive form. It is also a well-known harbor landmark tied to the island's legends.","narrative":"Nix's Mate Daybeacon marks a dangerous shoal near the convergence of three channels at the outer edge of Boston Harbor. It sits atop the remains of Nix's Mate, once a twelve-acre island and now a low rocky shoal. The marker has a rectangular granite base, about 67 by 32 feet and 16 feet high, topped by a truncated eight-sided wooden pyramid coated in concrete and painted black and white. Parts of the base date to work sponsored by Massachusetts in 1805 and the federal government in 1834. Lightning set the wooden pyramid on fire in 1841, and it was rebuilt. The Boston Marine Society pressed for such markers as government took over harbor navigation aids. The daybeacon was listed for its role in that effort and as a rare surviving permanent day marker. Erosion, storms and vandalism have left it listing about 20 degrees, with its base threatened.","period_of_significance":"1834-1952","architect_builder":null,"architectural_style":null,"criteria":["A","C"],"status_note":"Deteriorating: the structure lists about 20 degrees due to erosion and loss of infill, the concrete is spalled and cracked, and vandals' fires have damaged the interior center column. It continues to serve as a navigation aid.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:13:04.952864-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/82/7970/63797082/content/electronic-records/rg-079/NPS_MA/04000189.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/04000189/c508a75b9d-800.webp","url_1600":"https://nationalhistoricalregister.com/media/04000189/c508a75b9d-1600.webp","licence":"CC BY-SA 2.0","author":"Eric Kilby from Somerville, MA, USA","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Nixes_Mate_(18889971693).jpg\" rel=\"noopener\">Eric Kilby from Somerville, MA, USA</a>, <a href=\"https://creativecommons.org/licenses/by-sa/2.0\" rel=\"license noopener\">CC BY-SA 2.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Nixes_Mate_(18889971693).jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63797082","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q106475025"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/suffolk-county/nixs-mate-daybeacon-04000189/"}