{"id":171,"slug":"fort-willoughby-charlotte-amalie-u-s-virgin-islands","story":[{"heading":null,"paragraphs":["Fort Willoughby is the battery that changed flags — the Danish Prince Frederik's Battery, built in 1777–80 on the southeastern tip of what was then the Hurricane Hole peninsula, to guard the western entrance to St. Thomas harbor where Fort Christian could not reach. Its guns were meant for privateers; on March 3, 1801, it traded fire with HMS Arab and drove the British sloop off. Three weeks later the British took the island anyway, and renamed the battery Fort Willoughby.","The British came back in 1807 and stayed until 1815, rebuilding the battery and fortifying the whole of Hassel Island — the hornwork, gun platforms, barracks, magazine, and cookhouse that survive are largely their work, probably the only physical monuments of the Napoleonic-era British occupation left on American soil. The Danes cut the channel that made Hassel an island in 1865; the United States bought the whole territory in 1917.","The file keeps Fort Willoughby: the Danish battery that fought the Arab, the British occupation that rebuilt it, and the ruins that are the most intact Napoleonic-era fortifications in the Caribbean.","Fort Willoughby is the archive's Hassel Island file — the Danish battery, the two British occupations, and the ruins guarding St. Thomas harbor."]},{"heading":"Why this file matters","paragraphs":["Fort Willoughby is the archive's Hassel Island file — Prince Frederik's Battery, the 1801 skirmish, and the British fortifications that outlasted two empires.","A battery that changed names keeps its guns — the file's suggestion being that Willoughby's hold is the layering: Danish stone, British rebuild, American park, and the harbor entrance it watched for two centuries."]}],"name":"Fort Willoughby","aliases":["Fort Prince Frederick","Prince Frederik’s Battery"],"type":"FORT","type_label":"Fort","cats":["MILITARY_RUINS"],"groups":["ghost-towns","institutions"],"desc":"British rebuilding of a Danish harbor battery on Hassel Island.","full_desc":"A fort in Charlotte Amalie, U.S. Virgin Islands, Fort Willoughby is filed here for what the record attaches to it. British rebuilding of a Danish harbor battery on Hassel Island. The archive files it under military ruins. The dossier holds 1 documented fact — a documented spine with no haunting reports attached. Visitor status is unverified; confirm before making the trip.","address":null,"city":"Charlotte Amalie","county":"St. Thomas","state":"U.S. Virgin Islands","postal":null,"region":"Caribbean","lat":18.3419,"lon":-64.9307,"coord_kind":"MANUAL","status":"HISTORIC_SITE","access":"UNKNOWN","access_notes":null,"ownership":null,"website":null,"phone":null,"year_built":null,"year_opened":null,"year_closed":null,"year_demolished":null,"designation":null,"current_use":null,"research_notes":"Separate from Cowell’s Battery uphill. Nomination is historical documentation, not a current visitor-access source.","stage":"SOURCE_RESEARCH","quality":{"level":"MEDIUM","score":57.9,"dims":{"location_confidence":0.75,"identity_confidence":0.85,"historical_confidence":0.8,"source_quality":1,"paranormal_claim_provenance":null,"coordinate_confidence":0,"current_access_confidence":0,"freshness":0.65}},"claims":[],"history":[{"description":"The 1976 nomination documents British reconstruction of an earlier Danish waterfront battery during the Napoleonic-era occupation. Fort Willoughby's service record is documented — the entry belongs to the verified layer beneath the garrison lore. It's verified history: the dossier's load-bearing detail. Sources including 'Hassel Island Historic District National Register nomination' carry the record. The detail belongs to the verified spine of the entry.","evidence":"HISTORICALLY_VERIFIED","date_start":null,"date_end":null,"confidence":null,"source":{"name":"Hassel Island Historic District National Register nomination","url":"https://npgallery.nps.gov/GetAsset/5713d5de-e188-4204-9f24-b8da4216c2c4","publisher":"Virgin Islands Planning Office / National Park Service","type":"GOVERNMENT","authority":1}}],"legends":[],"entities":[],"events":[],"investigations":[],"encounters":[],"media":[],"persons":[],"visitor":{"tour_availability":"Verify before visiting","notes":"Access details are unverified; research before visiting.","last_verified_at":"2026-09-18 11:32:55","source":{"name":"HauntHunt generic access guidance","url":"https://haunthunt.com/about#access-guidance","publisher":"HauntHunt editorial","type":"DIRECTORY","authority":2}},"sources":[{"name":"Creque Marine Railway, Hassel Island, a Walking Tour","url":"https://stjohnhistoricalsociety.org/vol-ix-no-6-february-2008-creque-marine-railway-hassel-island-a-walking-tour-summarized-by-robin-swank/","publisher":"St. John Historical Society","type":"HISTORICAL_SOCIETY","authority":2},{"name":"Hassel Island Historic District National Register nomination","url":"https://npgallery.nps.gov/GetAsset/5713d5de-e188-4204-9f24-b8da4216c2c4","publisher":"Virgin Islands Planning Office / National Park Service","type":"GOVERNMENT","authority":1}],"conflicts":[],"wiki":{"title":"Fort Willoughby, U.S. Virgin Islands","url":"https://en.wikipedia.org/wiki/Fort_Willoughby%2C_U.S._Virgin_Islands","desc":"Historic fort on Hassel Island in the U.S. Virgin Islands","extract":"Fort Willoughby is a historic fort on Hassel Island in the U.S. Virgin Islands.","img":"https://thumb.wikimedia.org/wikipedia/commons/thumb/7/7b/FortWilloughbyHasselIslandUSVI.jpg/330px-FortWilloughbyHasselIslandUSVI.jpg?utm_source=en.wikipedia.org&utm_campaign=api&utm_content=thumbnail","score":75,"lat":18.1933,"lon":-64.5549},"counts":{"claims":0,"history":1,"legends":0,"entities":0,"sources":2}}