22. CWM PORTH CAVERNS (U) see pages 23 and 24 for surveys
Alt Names: Cwm Porth Woods Caves, Cwm-y-Porth Woods Caves
L = up to 60m
Cwm Porth Caverns constitute a classic series of caves formed under the gritstone cap rock. At least 35 entrances are identified in the literature as existing along the gritstone/limestone boundary in the woods to the south east of Cwm Porth Farm. None are easy to find in this dense forest and some (those isolated furthest from the gritstone/limestone boundary) virtually impossible to get at now. The caves are of a classic unconformity type and are characterised by collapse features with overhanging gritstone cliffs on the east side and a jumble of boulders in the base. These collapse dolines form the entrances to the caves. In most cases the cavities associated with them are fairly insignificant, however some of them interconnect thus forming large size passages up to 60m long. Drip water collecting in the caves seeps away through boulders and blind shafts in the floor and has been shown to resurge in a series of springs located below sites No 25 and No 26.
The caves that can still be located form six distinct groups. All of these caves were studied in some detail by Burke (9) and his identification letters have been related to the six groups.
(a) SN 9287 1191 A-F A large collapse feature with several entrances under a long gritstone cliff.
(b) SN 9287 1188 H-J A series of cavities located along the gritstone boundary. Some interconnected underground.
(c) SN 9287 1185 K-L Two interconnected entrances at one end of a large doline.
(d) SN 9288 1182 M-N A sizable stream sinks here after falling over the cliff on the east side. Sometimes called Waterfall Cave.
(e) SN 9288 1178 O-R An interconnected series of chambers running south from a large doline.
(f) SN 9288 1176 T-V Another interlinked series of cavities.
The sites Burke identified as W-AF, which should lie further to the north east are those which are now difficult to locate. A-G would appear to be the same as Cwm Porth Cave (site No 20).
References: 9 S, 12, 14, 18, 40 (M-N).
