- Category: Water Feature
- Type: Inland Water
- Latitude/Longitude: 52°49'6"N 3°59'27"W
- Eastings/Northings: 265926, 326416
- OS Grid: SH659264
- Mapcode Local: GBR 5W.VH0K
- Mapcode Global: WH567.NFQ1
Location and coordinates are for the approximate centre of Llyn Perfeddau within this administrative area.
Geographic features and populated places may cross administrative borders.