From Llethrid Bridge on the B4271 follow the river South until the sink is reached. The entrance is gated and the key is available from SWCC. The cave is liable to sudden and severe flooding.Current Access arrangements
Description
A narrow entrance leads to a 230 metre stream passage which is narrow and there are a number of squeezes. At the point where the stream disappears between the boulders, it is possible to climb to an upper series. This consists chiefly of two large chambers. The Great Hall, 65 to 100 metres long is extremely well decorated. A side passage leads to the second chamber - the Annex. From the Great Hall, a steep clay slope leads back to a continuation of the stream passage which shortly ends in a sump. Between the 1st and 2nd sump are mud chambers and two 10 metre pots. Sump 2 is 38 metres long and 4.5 metres deep and leads to a further 18 metres of passage and Sump 3 which remains unexplored.
History
Don Coase, BEC/SWCC, Aug. 1949; blocked by rockfall from 2003 until reopened by Andy Freem et al. 2021
Hydrology
The stream resurges at Wellhead
Conservation
SSSI: 0781 Coedydd Parkmill a Cwm Llethrid (Mixed)
British Caver 35, 52-54, 1962. Possible damage by quarrying.
Caves in Wales and the Marches (Dalesman), Jenkins, D.W. & Williams, A.M., 1963. Location description and brief details.
David Ede, Gower Vol.16, pp.64-55In Search of Caves
Wessex Cave Club Journal 8 (94), 42-44, 1964. Rescue
Belfry Bulletin 193, 10-12, 1964. Rescue
SVCC Newsletter 2 (1), p.3, 1964. Report on TV coverage of rescue, which resulted in closure of the cave (partly because coal miners called in to assist thought the cave suicidal due to lack of props).
British Caver 43, 1966
CDG nl.30, 1974
CDG nl.32, 1974
Three Below Gower, 1991, Ch.21 Llethrid Swallet, Ultima Thule
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