- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 51°42'52"N 3°58'14"W
- Eastings/Northings: 263955, 203606
- OS Grid: SN639036
- Mapcode Local: GBR GX.N4RJ
- Mapcode Global: VH4JX.457F
Location and coordinates are for the approximate centre of Cwm Nant-ddu within this administrative area.
Geographic features and populated places may cross administrative borders.