- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 52°2'30"N 4°39'24"W
- Eastings/Northings: 217896, 241493
- OS Grid: SN178414
- Mapcode Local: GBR CZ.FKMD
- Mapcode Global: VH2MW.7YK1
Location and coordinates are for the approximate centre of Cwm Bastwn within this administrative area.
Geographic features and populated places may cross administrative borders.