Powys
, Northern Outcrop - East (Morlais to Abergavenny)
map using leaflet map:
Sink
Pothole
Access
The doline is easiest found by following the B4560 road (from Beaufort to Llangynidr) to just before the turning to Llangattwg village. Opposite a track on the left, there is a small outcrop running East on the right. Follow the outcrop for several hundred metres and then turn North. The sink is the largest of all the swallets in this region.
Description
This cave, in the bottom of an active sink, is high up on the moor and consists of a dig in boulders for almost its full length. 17m pitch in scaffolded shaft, then 10m pitch (fixed iron ladders still in place), to horizontal passage on impervious beds (thought to be around 5m thick) which holds up breakthrough to more cavernous beds below...
History
HCC dig 2008-2014-
Hydrology
The swallet takes around 86,400 litres of water per day [001 cumecs] and it reappears somewhere in Remembrance Series (top end of Turkey passage) in Agen Allwedd. The main water can be heard, but not seen, in the cave; that in the cave drains in several places through the floor.
