| Cwm Hengae | |
|---|---|
| Cwm Llefenni | |
 Looking west from Aberllefenni quarry along Cwm Hengae | |
| Geography | |
| Location | Aberllefenni |
| Country | Wales |
| Coordinates | 52°40′23″N 3°49′08″W / 52.673°N 3.819°W |
| River | Afon Llefenni |
Cwm Hengae is a valley that runs roughly north-west from the village of Aberllefenni in Wales. The Afon Llefenni river runs along the valley and several slate quarries occupy the valley sides. The Roman road Sarn Helen ran along the valley, connecting Aberllefenni with Dolgellau.[1]
- ^ An Inventory of the Ancient Monuments in Wales and Monmouthshire: VI – County of Merioneth. Royal Commission on the Ancient and Historical Monuments of Wales. 30 December 1921. pp. 164–. GGKEY:U89CDD2G7U4.