L:561
V:104

Pwll Dwfn, Deep Pot


NGR: SN 83319 16484
397 m.asl

Powys , Northern Outcrop - West (Black Mountain)
 map using leaflet map:
Pothole
Access Small entrance in dry valley near track. Follow the old tramway up from Carreg Haffes farm towards the stone walling and as the path crosses the top of the Dan-yr-Ogof dry valley, look for the entrance a few yards from the track on the right.
Description This is a vertical pothole, originally as 5 pitches down to a sump, but now with an alternative 3 pitch route (no easier, CUCC Old Flyover, with a tight section and 47m pitch). Above the sump (normally 4m deep), Enterprise Aven series rises 50m; other aven climbs have also topped out..
History Wessex Caving Club & SWCC, 1946; Cardiff UCC 2010; CDG et al. 2007,2011-2020 (Poacher's Passage, 2011; Enterprise Aven 2012-2013)
Hydrology Traced to Washing Machine in DYO (~80m lower)
Conservation SSSI: 0854 Mynydd Du (Mixed) Biological records
Gallery

Brendan Marris
2008
CC BY-SA 3.0
2014
Mark Burkey

5th pitch
Survey
Dolphin & Low, 1947 (also BCRA Trans 4(1/2), 1977)
CPC, 1962
CDG nl 183, sump.
Wilton-Jones & Davies, 2025 Grade 6, plan, elevations, rigging
References
Belfry Bulletin, 195, 5-8. Description and survey
SWCC Newsletter, 20 August 1947
Wessex Cave Club Circular No.6 (NS), 1947 P.Dolphin, C.Low, J.Lander, N.Paddock
Wessex Cave Club Circular No.8 (NS), 1947
British Caver, 17, 1947, p.35,75, Dolphin,P. & Low, C., Pwll Dwfn, Glyntawe, a South Wales Pot
Cullingford, C.H.D. (1951) Exploring Caves,pp.73
Britain Underground, 1953
Jnl CravenPC 3(2), pp.63-65, 1962, D.M.Judson. Pwll Dwfn
British Caver, 41, 1965, p.19
Caves in Wales and the Marches (Dalesman), Jenkins, D.W. & Williams, A.M. 1st Ed.1963, p.44
CDG nl.24, p.24 (1972)
Caves of South Wales, 1995, p.109
Selected Caves of Britain and Ireland, 1997
Welsh Sump Index 2006
Descent 214, p.10, Martyn Farr, New route in Pwll Dwfn ['CUCC Old' Flyover/Bypass]
CDG nl 183, pp.20-22 (2012)
Brendan Marris Caves of South Wales
SWCC 75th Anniversary Publication, Vol.2, pp.205-209, (2021)Tony Baker, Gareth Davies, Pwll Dwfn Extensions
Wilton-Jones, T.(2025) Pwll Dwfn description, survey, photos
Descent 305?, p.tbc, (2025) Tarquin Wilton-Jones, Pwll Dwfn ?
Search for further records Browse registry map
Cambrian Cave Registry entry 275
 Comment? Email registrar@cambriancavingcouncil.org.uk © Caving Wales ⓗ Ogofa Cymru