Thacher Island Twin Lights
E177483
Thacher Island Twin Lights are a historic pair of lighthouses off Cape Ann in Massachusetts, notable as one of the last surviving twin light stations in the United States and a prominent aid to navigation since the 18th century.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Thacher Island Twin Lights canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T1561807 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Thacher Island Twin Lights Context triple: [Cape Ann, hasLandmark, Thacher Island Twin Lights]
-
A.
Anacapa Island Lighthouse
Anacapa Island Lighthouse is a historic navigational beacon on Anacapa Island off the coast of California, guiding ships through the Santa Barbara Channel.
-
B.
Robbins Reef Lighthouse
Robbins Reef Lighthouse is a historic offshore beacon in New York Harbor that has guided ships since the 19th century and is famed for its distinctive “sparkplug” design and the story of its longtime keeper, Kate Walker.
-
C.
South Manitou Island Lighthouse
South Manitou Island Lighthouse is a historic navigational beacon on South Manitou Island in Lake Michigan, known for guiding ships through the Manitou Passage and for its preserved 19th-century architecture.
-
D.
Outer Island Light
Outer Island Light is a historic lighthouse located on Outer Island in Wisconsin’s Apostle Islands, guiding ships navigating Lake Superior.
-
E.
Devils Island Light
Devils Island Light is a historic lighthouse located on Devils Island in Wisconsin’s Apostle Islands, guiding ships through the waters of Lake Superior.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Thacher Island Twin Lights Target entity description: Thacher Island Twin Lights are a historic pair of lighthouses off Cape Ann in Massachusetts, notable as one of the last surviving twin light stations in the United States and a prominent aid to navigation since the 18th century.
-
A.
Anacapa Island Lighthouse
Anacapa Island Lighthouse is a historic navigational beacon on Anacapa Island off the coast of California, guiding ships through the Santa Barbara Channel.
-
B.
Robbins Reef Lighthouse
Robbins Reef Lighthouse is a historic offshore beacon in New York Harbor that has guided ships since the 19th century and is famed for its distinctive “sparkplug” design and the story of its longtime keeper, Kate Walker.
-
C.
South Manitou Island Lighthouse
South Manitou Island Lighthouse is a historic navigational beacon on South Manitou Island in Lake Michigan, known for guiding ships through the Manitou Passage and for its preserved 19th-century architecture.
-
D.
Outer Island Light
Outer Island Light is a historic lighthouse located on Outer Island in Wisconsin’s Apostle Islands, guiding ships navigating Lake Superior.
-
E.
Devils Island Light
Devils Island Light is a historic lighthouse located on Devils Island in Wisconsin’s Apostle Islands, guiding ships through the waters of Lake Superior.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
historic site
ⓘ
lighthouse station ⓘ |
| accessibleBy | boat ⓘ |
| associatedWithEvent | development of early American coastal navigation ⓘ |
| automated | 1980 ⓘ |
| category |
Lighthouses in Massachusetts
ⓘ
Twin lighthouses in the United States ⓘ |
| constructionMaterial | granite ⓘ |
| country |
United States of America
ⓘ
surface form:
United States
|
| currentTowersCompleted | 1861 ⓘ |
| focalHeight |
about 148 feet
ⓘ
about 45 meters ⓘ |
| governingBody |
Thacher Island Association (for preservation and access)
ⓘ
surface form:
Thacher Island Town Committee
|
| hasComponent |
north tower
ⓘ
south tower ⓘ |
| hasNameOrigin | named after Anthony Thacher ⓘ |
| hasVisitorAccess | yes ⓘ |
| height |
about 124 feet
ⓘ
about 41 meters ⓘ |
| lightCharacteristic | flashing white light ⓘ |
| listedOn | National Register of Historic Places ⓘ |
| locatedIn |
Cape Ann
ⓘ
Massachusetts ⓘ Thacher Island NERFINISHED ⓘ |
| locatedInBodyOfWater | Atlantic Ocean ⓘ |
| managedBy |
Thacher Island Association
ⓘ
United States Coast Guard ⓘ
surface form:
U.S. Coast Guard
|
| marking | unpainted gray granite ⓘ |
| nearbyCity |
Gloucester, Massachusetts, United States
ⓘ
surface form:
Gloucester, Massachusetts
Rockport, Massachusetts ⓘ |
| notableFor |
being one of the last surviving twin light stations in the United States
ⓘ
marking the approach to Cape Ann and Massachusetts Bay ⓘ |
| NRHPDesignationYear | 1971 ⓘ |
| NRHPType |
U.S. National Historic Landmark District
ⓘ
surface form:
National Historic Landmark District
|
| numberOfLighthouses | 2 ⓘ |
| originalConstructionYear | 1771 ⓘ |
| ownedBy |
Rockport, Massachusetts
ⓘ
surface form:
Town of Rockport, Massachusetts
|
| partOf |
Rockport, Massachusetts
ⓘ
surface form:
Town of Rockport, Massachusetts
|
| purpose | aid to navigation ⓘ |
| region | New England ⓘ |
| status | active aid to navigation ⓘ |
| towerShape | conical tower ⓘ |
| USCGNumber |
1-2950 (south tower)
ⓘ
1-2955 (north tower) ⓘ |
| yearLit | 1771 ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Thacher Island Twin Lights Description of subject: Thacher Island Twin Lights are a historic pair of lighthouses off Cape Ann in Massachusetts, notable as one of the last surviving twin light stations in the United States and a prominent aid to navigation since the 18th century.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.