Powys
, Northern Outcrop - Central (Penwyllt to Penderyn)
map using leaflet map:
Sink
Doline
Access
From the dry river bridge at Bridge Cave, follow the track to Pant Mawr House ruins, until it leaves Sarn Helen Road, then carry on due North following the Western of a pair of parallel lined walls for about 365 metres to a point where it turns NE to meet another wall. Then go WNW for about 75 metres following a dry shallow valley with several collapse features and where a stream can be heard underground most of the way.
Description
A small mountain stream sinks in a region with several collapse holes, which probably all take water in flood. It is a blind, shallow dry valley with slightly dry ground to the West, where the dry valley continues. The stream could be the same one as flows in the swallet and pothole to the WSW. A likely dig.
