Turn Left along the Sarn Helen, heading South West. Initially the road is through the forestry and has some of the biggest puddles you could ever wish for!
It then comes out on open common, where the track is very rutted. It then bears Left, through a couple of gates, where you come to an old abandoned farm house. Here it starts dropping down a long hill back to the B4242. Turn Left back up this road until you get to the canal (where it passes under a bridge under the New Road). Here you can pick up the canal bike path, which apart from a small stretch of road, runs all the way back to the start point.