- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 53°4'19"N 4°9'1"W
- Eastings/Northings: 256035, 354936
- OS Grid: SH560549
- Mapcode Local: GBR 5P.BD98
- Mapcode Global: WH550.61XM
Location and coordinates are for the approximate centre of Llyn Cwellyn within this administrative area.
Geographic features and populated places may cross administrative borders.