- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 53°8'31"N 3°34'15"W
- Eastings/Northings: 295019, 361687
- OS Grid: SH950616
- Mapcode Local: GBR 6F.631G
- Mapcode Global: WH661.39T3
Location and coordinates are for the approximate centre of Llyn Cefn within this administrative area.
Geographic features and populated places may cross administrative borders.