The 5 mile walk climbs gently from the Lower to Upper Lliw Reservoirs on a good metaled path and kissing gates. The Upper Dam and Reservoir and the source of the river is on the high moorland common near Penlle’r Castell to the West of the Filltir Fain road that crosses Mynydd y Gwair at over 1,000 feet above sea level.
The return is on the same path as far as the Lower Reservoir, when we walk down steps and along a rough path to the west of the reservoir leading to the Lower Dam. An easier alternative is continue on the metaled path to the café for refreshments.
