- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 52°54'46"N 4°2'23"W
- Eastings/Northings: 262939, 336990
- OS Grid: SH629369
- Mapcode Local: GBR 5T.NH57
- Mapcode Global: WH55T.X1HT
Location and coordinates are for the approximate centre of Llyn Tecwyn Isaf within this administrative area.
Geographic features and populated places may cross administrative borders.