{"nrhp_refnum":"72000864","name":"Castle Williams","other_names":["The Tower"],"category":"building","location":{"address":"Governors Island","address_restricted":false,"city":"New York","county":"Manhattan","state":"NY","lat":40.692844896000054,"lon":-74.01939356399998,"geom_source":"nps_gis"},"listed_date":"1972-07-31","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Military","Architecture"],"significance_levels":["national"],"summary":{"what_it_is":"Castle Williams is a circular red sandstone fort on the northwest point of Governors Island in New York Harbor, begun in 1807 and completed in 1811. It was designed and built by Lieutenant Colonel Jonathan Williams and was originally called \"The Tower\".","why_significant":"The nomination presents it as an unusual military fortification and a notable example of a massive masonry bastion that still serves a useful function. Completed in 1811 with more than one hundred cannon, it was one of the reasons the British fleet did not attempt an assault on New York during the War of 1812. With its twin, Castle Clinton, it guarded the waterway between Governors Island and New York City.","narrative":"Castle Williams is a round, three-story fort of red Newark sandstone on the northwest point of Governors Island, in New York Harbor. Begun in 1807 and finished in 1811, it was designed and built by Lieutenant Colonel Jonathan Williams, then Chief Engineer of the U.S. Army. The walls form three-fifths of a circle about two hundred feet across, forty feet high and eight feet thick at the base, with arched casemates supporting three tiers of guns. Two straight walls close the enclosure on the landward side, topped by a bartizan. Originally called \"The Tower\" and nicknamed \"The Cheesebox,\" it carried more than one hundred cannon and, with Castle Clinton in the Battery, guarded the waterway to New York City. It was cited as a reason the British fleet did not attack the city during the War of 1812. Repairs came in 1833, 1836 and 1912, when interior buildings were removed, the fort became a military prison, and concrete galleries were added.","period_of_significance":"19th Century (begun 1807; completed 1811)","architect_builder":"Lieutenant Colonel Jonathan Williams","architectural_style":null,"criteria":[],"status_note":"Listed in good condition, altered, on its original site, and occupied. Converted into a military prison in 1912, with concrete galleries added inside the walls. Owned by the U.S. Coast Guard.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:39.862639-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/72000864.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/72000864/616a3865fa-800.webp","url_1600":"https://nationalhistoricalregister.com/media/72000864/616a3865fa-1600.webp","licence":"Public domain","author":"Jim.henderson","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Castle_Williams_SIF_jeh.JPG\" rel=\"noopener\">Jim.henderson</a>, Public domain, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Castle_Williams_SIF_jeh.JPG"},"district":{"nrhp_refnum":"85002435","name":"Governors Island","url":"https://nationalhistoricalregister.com/districts/new-york/governors-island-85002435/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75319350","wikipedia":"https://en.wikipedia.org/wiki/Castle_Williams","wikidata":"https://www.wikidata.org/wiki/Q1049532"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/manhattan/castle-williams-72000864/"}