- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 52°57'4"N 3°42'2"W
- Eastings/Northings: 285844, 340682
- OS Grid: SH858406
- Mapcode Local: GBR 68.L1K1
- Mapcode Global: WH66Y.422S
Location and coordinates are for the approximate centre of Llyn Celyn within this administrative area.
Geographic features and populated places may cross administrative borders.