This is a well marked path with many options for making it longer or shorter. There are three starting car parks and my route took in two of them. Three of the waterfalls involve steep steps down into the valley and back up again.
The Clyn-Gwyn car park (Grid Ref: SN 92042 10695) has a free area by the road which gets very crowed. If you take the track towards the bunk house, there is a second pay car park and outdoor cafe. We parked here and took the sign posted path down to the waterfalls.
We also walked to the Cwm Porth care park (which discourages camper vans) to look at the caves where the rive goes underground and many potholers start their expeditions.