- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 52°22'13"N 3°58'34"W
- Eastings/Northings: 265546, 276530
- OS Grid: SN655765
- Mapcode Local: GBR 8X.RTW5
- Mapcode Global: VH4FM.1P69
Location and coordinates are for the approximate centre of Cwm Wern-Ddu within this administrative area.
Geographic features and populated places may cross administrative borders.