Waterfall Cave

Location
From the Drum and Monkey pub, head up the Black Rock road until you reach the entrance to the Black Rock Quarry. It has an obvious "KEEP OUT" sign. Fear not! The sign is not intended for cavers but for travellers who have a habit of blocking the owners access to his sheds etc.

Walk to the left and up to the quarry face, continue until you see a small cave with a stream issuing from it. Downstream is what looks like a concrete drainage tunnel. Either crawl down the tunnel or go up over it and down into the quarry the other side. Waterfall cave is where the stream goes and it is only 3 or 4 metres from the other end of the concrete tunnel.

SO 21274 12497 or 51.805543N, 3.143212W

Access
Not gated.

Description
105 metres long. If you are lucky, just past the entrance you might see what looks like a very large moths cocoon hanging someplace. This is not a moths cocoon but a very large spiders egg sack and someplace mother will be guarding it. The spider in question is Meta Menardi, and Waterfall Cave has a large population of them. Pictures of Meta Menardi.

This cave is not as sharp as it used to be, for someone (who will remain nameless - but I do know who) took a hammer and chisel to all the tight grabby sharp bits!

Mostly this is a stooping passage with phreatic shelving. It has a clean washed pebble floor and the stream is seldom more than ankle deep. After about 40 metres there is the first small cascade which drops about 30cm. The next 4 metres are a shallow (0.4m) pool, ending with a small rock bridge. A short way on is an oxbow, the left hand path is too tight, the right hand path is a low crawl in a cascade which drops about 0.4m.

The passage continues for about another 5m, after which is a third cascade, about 0.3m, after which the water becomes deeper again for about 6m.

The passage continues for another 2m after which a drop of 2.5m ends in a large chamber with many fallen boulders, the largest of which is in a place it is possible to reach with ones feet as one climbs down, however this is an awkward manoeuvre and persons of smaller stature will not be able to manage the stretch. The drop also provides the waterfall which gives the cave its name.

The chamber is called Siambri Pen y Mochyn, it is about 12m long and 10 wide, and about 4.5m high. The far end has many fallen blocks, towards the left there is a way down behind a boulder choke, this leads to another low chamber after which the stream sinks. Further on are squeezes into other smaller chambers, a final collapsed chamber and a terminal boulder choke. This point is very close to the Clydach Gorge.

History
The cave was first explored by BNSSS in the early 1960s. Surveyed by BNSS in 1960s. Recent survey in CSS Records (19) 1992.