- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 51°58'29"N 4°0'4"W
- Eastings/Northings: 262638, 232608
- OS Grid: SN626326
- Mapcode Local: GBR DW.KL5B
- Mapcode Global: VH4HJ.LMKD
Location and coordinates are for the approximate centre of Cwm yr Efail within this administrative area.
Geographic features and populated places may cross administrative borders.