L:70
V:

Twll Gwynt Oer, Cold Wind Hole


NGR: SN 85874 15958
368 m.asl

Powys , Northern Outcrop - Central (Penwyllt to Penderyn)
map using leaflet map:
Cave
Access In the dry valley behind the main Penwyllt Quarry. The entrance is marked by spoil.
Description Capped 10m shaft in a small shakehole leads to a miniature streamway. Upstream (north) reaches a boulder collapse after approx 30m. Downstream , the passage enters a constricted sump after a similar distance, which receives occasional (chemical) attention. The water flowing in this small cave appears in Cwmdwr Jama via the upstream choke.
History Brian Jopling, SWCC 1979/80
Hydrology Tests
Conservation SSSI: 0099 Ogof Ffynnon Ddu (Mixed)
Gallery

Brendan Marris
2008

Gary Evans
2020
Survey
SWCC Newsletter 93, 1981
References
CDG nl.52, p.29 (1979)
SWCC Newsletter 93, 1981
Catalogue of Speleological Sites...between...A4067...Pant Mawr Moor, Gary Evans (2021),p.79
Cambrian Cave Registry entry 348
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