- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 51°41'27"N 2°53'41"W
- Eastings/Northings: 338246, 199526
- OS Grid: ST382995
- Mapcode Local: GBR JB.4LJX
- Mapcode Global: VH79V.SR0G
Location and coordinates are for the approximate centre of Pen-y-llyn Pool within this administrative area.
Geographic features and populated places may cross administrative borders.