- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 53°0'42"N 3°59'11"W
- Eastings/Northings: 266828, 347896
- OS Grid: SH668478
- Mapcode Local: GBR 5W.GB3T
- Mapcode Global: WH558.QKWF
Location and coordinates are for the approximate centre of Llyn Terfyn within this administrative area.
Geographic features and populated places may cross administrative borders.