- Category: Geographic Feature
- Type: Valley
- Latitude/Longitude: 52°59'2"N 4°8'12"W
- Eastings/Northings: 256649, 345092
- OS Grid: SH566450
- Mapcode Local: GBR 5P.J3KT
- Mapcode Global: WH55D.F8B9
Location and coordinates are for the approximate centre of Cwmystradllyn within this administrative area.
Geographic features and populated places may cross administrative borders.