This cave was exposed by quarrying in 1961 and is a remnant of a larger system of which Ogof Rhaeadr Ddu and Ogof Craig Ddu were once a part. A short stream passage which is navigated by crawling for most of it's length drops 2.5m into Siambri Pen Y Mochyn Chamber. The cave is noted for a sizable colony of Meta Menardi spiders
in the entrance passage.
SO 21274 12497
The water from this cave (the same as that from Ogof Rhaeadr Ddu) resurges through boulders cascading down into the Clydach Gorge opposite Ogof Clogwyn. The cave was first discovered in 1961 when the quarry face at Blackrock intersected the passage and provided two entrances into it. This was explored by Mel Davies and the BNSSS. By 1985 when work in the quarry ceased, just over 100m of the lower cave remained - named Waterfall Cave, while at the upstream end 300m of cave known as Ogof Rhaeadr Ddu was left. Later the quarry was used to take landfill, with a concrete pipe being laid to take water from Ogof Rhaeadr Ddu beneath the infill to emerge and flow into the entrance to Waterfall Cave on the South side of the quarry.
Waterfall Cave is located in the South side of the disused Blackrock Quarry. The entrance is located at the base of an exposed quarry face directly below the 30mph signs that are located on the Blackrock road that runs beside the quarry. The stream from Ogof Rhaeadr Ddu emerges from a concrete pipe to flow a short distance before entering the cave.
Clydach Gorge Google map showing the location of Waterfall Cave and other caves in the area
The cave is not gated and is rarely visited.
A gated entrance to the quarry leads to a flat area that is now starting to become overgrown. Heading to the South end of the quarry a steep overgrown slope leads down to a cliff face with the Blackrock road just above. The stream can be seen emerging from the concrete pipe at the base of the slope and flows a short distance to enter the cave through boulders. A squeeze through the rocks at the entrance leads into a low passage that meanders and drops via a series of three small cascades. The passage is quite sharp with prominent phreatic shelves present throughout it's length. The entrance series is noted for a profusion of large Meta Menardi spiders which are the highlight of the entrance passage. After about 80 metres the hands and knees crawl reaches a 2.5m cascade down into Siambri Pen Y Mochyn Chamber, where some large boulders can be dropped onto from the crawl. The chamber is about 12 metres square and ends at a pile of large boulders. The stream sinks into the floor of the chamber and a squeeze through the boulders in the centre of the chamber leads into a smaller lower chamber. Here the stream sinks into rocks, while a climb up on the right hand wall of the second chamber leads to a smaller final chamber.
No tackle required.
Waterfall Cave Survey - For Historical Interest Only
Cambrian Cave Registry for Waterfall Cave
UK Caving Wiki Entry for Waterfall Cave
Caves of South Wales
| Tim Stratford | ISBN: 0904405354 | Published by Cordee
The Caves of Clydach
| Tony Oldham
A Caver's View of the Clydach River
| Theo Schuurmans | Cwmbran Caving Club
An Exploration Journal of Llangattwg Mountain
| Chelsea Spelaeological Society Records V19 - 1992
The quarry was infilled with building rubble and some of this waste has been washed into the cave.
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