All walks › Bannau Brycheiniog: Black Mountains
Bannau Brycheiniog: Black MountainsGrwyne Fawr Reservoir
A long track up a remote valley to a small reservoir under Waun Fach, in one of the emptiest corners of the Black Mountains.
- Distance
- 5.6 mi / 9 km
- Time
- 3 hr 10
- Ascent
- 300 m
- Difficulty
- Demanding
- Shape
- There and back
Where it is
The circle shows the general area, not the exact start. Use the directions link below to get to the car park itself. Contours and paths shown are OpenTopoMap, drawn from OpenStreetMap data.
The route
A forestry and moorland track runs up the valley from the car park to the dam. Continue onto the ridge if equipped, or reverse the outward route.
Worth knowing
- The valley road in is single track for several miles and slow going.
- The reservoir was built by a narrow gauge railway whose formation is the track you walk on.
- No facilities and no signal from the moment you leave Llanbedr.
What you’ll see
The dam and reservoir, forestry giving way to open moor, and the ridge above.
Background
Built between 1912 and 1928 to supply Abertillery, using a temporary railway up the valley. The dam is the highest reservoir in the Bannau.