- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 52°47'56"N 3°23'50"W
- Eastings/Northings: 305891, 323293
- OS Grid: SJ058232
- Mapcode Local: GBR 6N.WP8G
- Mapcode Global: WH78S.SXF3
Location and coordinates are for the approximate centre of Cwm Hirnant within this administrative area.
Geographic features and populated places may cross administrative borders.