This is the woodland and series of waterfalls below Devil's Bridge where the River Mynach drops 90m down a steep, narrow ravine. After all the recent rain there was plenty of water rushing down on the day I visited.
According to legend, the original bridge was built after an old woman lost her cow and saw it grazing on the other side of the river. The Devil appeared and agreed to build a bridge in return for the soul of the first living thing to cross it. When the bridge was finished, the old woman threw a crust of bread over the river, which her dog rushed across to retrieve, thus becoming the first living thing to cross it and the Devil was left with claiming just the soul of the dog.
I could think of a few people I would have preferred to go across before the doggie.
By the way, as I'm far too lazy to carry a tripod up and down the hundreds of steps all the pictures are taken having wedged the camera against a handy tree or the path hand rail.