Starting at the Penbont Car Park, we will make our way along the Garreg-Ddu reservoir before turning up to the Nant Methan mine area. From here we have a steep climb up Cefn Llanerchtynewedd before dropping down to Nant Brithgwm. Another climb up Esgair Brithgwm gives us views down to the Craig Goch Dam & reservoir. We cross over the Dam and return to our cars by way of Devil's Gulch on the cycle track, by the side of Penygarreg Reservoir.
A visit to the Nant Methan mines would be possible for anyone not having visited them before, though it is not part of the planned route and would add slightly to the mileage. The track down to Nant Brithgwm is often wet and muddy, even in summer. There is quite a lot of bracken around so watch out for ticks! There are toilets at Craig Goch dam. Refreshments are available from the Visitor Centre at the end of the walk if wanted (NB: Penbont Tearooms are closed)