Pen-y-garreg Reservoir
E239821
Pen-y-garreg Reservoir is a scenic man-made lake in the Elan Valley of mid Wales, known for its historic stone dam and role in the region’s water supply system.
All labels observed (4)
| Label | Occurrences |
|---|---|
| Pen-y-garreg Dam | 4 |
| Pen-y-garreg Reservoir canonical | 4 |
| Pen-y-Garreg Reservoir | 1 |
| Pen-y-garreg Dam valve tower | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T2115146 — 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: Pen-y-garreg Reservoir Context triple: [Rhayader, hasNearbyReservoir, Pen-y-garreg Reservoir]
-
A.
Garreg Ddu Reservoir
Garreg Ddu Reservoir is a scenic man-made lake in the Elan Valley of mid-Wales, known for its distinctive submerged dam and role in supplying water to the city of Birmingham.
-
B.
Abbeystead Reservoir
Abbeystead Reservoir is a man-made lake in Lancashire, England, known for its scenic setting within the Forest of Bowland and its role in regional water supply.
-
C.
Ladybower Reservoir
Ladybower Reservoir is a large Y-shaped drinking-water reservoir in the Upper Derwent Valley of Derbyshire, England, known for its distinctive plughole spillways and surrounding Peak District scenery.
-
D.
Harperrig Reservoir
Harperrig Reservoir is a man-made freshwater reservoir in the Pentland Hills of Scotland, used for water supply, fishing, and recreation.
-
E.
Howden Reservoir
Howden Reservoir is a large man-made lake in Derbyshire’s Peak District, known as part of the Upper Derwent Valley chain of reservoirs supplying water to nearby cities and popular for its scenic surroundings and outdoor recreation.
- 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: Pen-y-garreg Reservoir Target entity description: Pen-y-garreg Reservoir is a scenic man-made lake in the Elan Valley of mid Wales, known for its historic stone dam and role in the region’s water supply system.
-
A.
Garreg Ddu Reservoir
Garreg Ddu Reservoir is a scenic man-made lake in the Elan Valley of mid-Wales, known for its distinctive submerged dam and role in supplying water to the city of Birmingham.
-
B.
Abbeystead Reservoir
Abbeystead Reservoir is a man-made lake in Lancashire, England, known for its scenic setting within the Forest of Bowland and its role in regional water supply.
-
C.
Ladybower Reservoir
Ladybower Reservoir is a large Y-shaped drinking-water reservoir in the Upper Derwent Valley of Derbyshire, England, known for its distinctive plughole spillways and surrounding Peak District scenery.
-
D.
Harperrig Reservoir
Harperrig Reservoir is a man-made freshwater reservoir in the Pentland Hills of Scotland, used for water supply, fishing, and recreation.
-
E.
Howden Reservoir
Howden Reservoir is a large man-made lake in Derbyshire’s Peak District, known as part of the Upper Derwent Valley chain of reservoirs supplying water to nearby cities and popular for its scenic surroundings and outdoor recreation.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
man-made lake
ⓘ
reservoir ⓘ |
| basinCountry | United Kingdom ⓘ |
| connectedTo |
Birmingham Corporation water supply scheme
ⓘ
linked to:
Derwent Valley Water Board
|
| constructionMaterial | stone ⓘ |
| country | Wales ⓘ |
| createdBy |
Pen-y-garreg Dam
ⓘ
linked to:
Pen-y-garreg Reservoir
|
| drainsTo | River Elan ⓘ |
| ecosystemType | freshwater lake ⓘ |
| environment | upland valley landscape ⓘ |
| hasAccess | Elan Valley Trail ⓘ |
| hasFeature |
historic stone dam
ⓘ
valley-side masonry dam ⓘ |
| hasNearbyFacility |
car park
ⓘ
viewing area ⓘ |
| hasNearbyStructure |
Pen-y-garreg Dam valve tower
ⓘ
linked to:
Pen-y-garreg Reservoir
|
| hasPart |
Pen-y-garreg Dam
ⓘ
linked to:
Pen-y-garreg Reservoir
|
| hasRecreationRoute | circular walking paths around reservoir ⓘ |
| hasViewpoint | Pen-y-garreg Dam tower ⓘ |
| knownFor |
historic waterworks
ⓘ
picturesque dam architecture ⓘ scenic views ⓘ |
| locatedIn |
Elan Valley
ⓘ
Powys ⓘ mid Wales ⓘ |
| managesWaterFor | Birmingham ⓘ |
| near |
Caban-coch Reservoir
ⓘ
linked to:
Caban Coch Reservoir
Craig Goch Reservoir ⓘ Garreg-ddu Reservoir ⓘ
linked to:
Garreg Ddu Reservoir
|
| operator | Dŵr Cymru Welsh Water ⓘ |
| ownedBy | Dŵr Cymru Welsh Water ⓘ |
| partOf |
Elan Valley Estate
ⓘ
Elan Valley Reservoirs ⓘ
linked to:
Elan Valley reservoirs
Elan Valley dams and reservoirs complex ⓘ
linked to:
Elan Valley reservoirs
Elan Valley water supply system ⓘ
linked to:
Elan Valley reservoirs
|
| purpose |
drinking water storage
ⓘ
public water supply ⓘ |
| region |
Elan Valley, Powys
ⓘ
linked to:
Elan Valley
|
| subjectTo | UK reservoir safety regulations ⓘ |
| tourismType | rural tourism attraction ⓘ |
| usedFor |
angling
ⓘ
flow regulation ⓘ hydraulic head regulation ⓘ recreation ⓘ walking ⓘ wildlife observation ⓘ |
| watercourse | River Elan ⓘ |
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: Pen-y-garreg Reservoir Description of subject: Pen-y-garreg Reservoir is a scenic man-made lake in the Elan Valley of mid Wales, known for its historic stone dam and role in the region’s water supply system.
Referenced by (10)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Pen-y-garreg Reservoir
linked to: Pen-y-garreg Reservoir
linked to: Pen-y-garreg Reservoir
linked to: Pen-y-garreg Reservoir
linked to: Pen-y-garreg Reservoir
linked to: Pen-y-garreg Reservoir