The Rhymney Valley Ridgeway is a waymarkedpath which provides a high-level diversion from the Cistercian Way through Caerphilly. It goes through ancient beech woods and along the ridge of Rudry Common with superb views to the coast and the mountains.
Follow the main route from Risca through Machen. When you cross the river, instead of taking the road to the right, turn left along a lane.
The Rhymney Valley Ridgeway goes south from here to Draethen and Ruperra. Ruperra Castle and the woods are worth a visit, but you can cut the angle off. Stay with the lane as it bears right. Cross a minor road and take a hollow lane up through the trees. At ST21124 88794 cross another minor road and take the track ahead of you. Follow the main track to a fork at 21105 88447. Bear left and follow the track into the forest.
This area is full of old lead workings, some of them Roman. At 21401 87612 a path into the trees to your left leads to a fenced-off shaft with a huge beech tree growing out of it.
At 20798 87110 turn right then left along a rough track. This becomes a minor road to the Maen Llwyd, an excellent pub with a long history. Cross the road in front of the pub at 20134 86625. Go up the steps, round the car park, over a stile (20101 86594) , across a forest road and up some more steps. Follow the track into the forest.
At 19823 86479 you rejoin the Rhymney Valley Ridgeway. The path is clearly waymarked from here through the woods and along the ridge. Crossing the main road from Cardiff to Caerphilly is VERY dangerous - take your time, the traffic goes fast. A little to your left the path continues past Cefncarnau-fach farm.
Turn right in the middle of the golf course (well signposted). Walk across the golf course and up a steep slope through scrubby trees. Turn left at the top of the slope then right to walk down a steep track. Cross the side road ahead of you and walk down the main Caerphilly road for a few yards then take the track to the left.
When the path forks turn right. Walk down a slope, turn left on a side road and follow this down to join the main road. From here, follow the main Caerphilly-Pontypridd route.