, Northern Outcrop - East (Morlais to Abergavenny)
map using leaflet map:
In open moorland, West of Trefil village.
A deep swallet with a 12m cliff. Two entrances in the base of the cliff unite in Cullingford's Chamber. There is a further crawl and a 5m drop leading to a boulder choke in a small chamber. Water from here resurges at the Sion-Sieffri Reservoir to the South of Trefil village.
Extended in 1987 through a series of rifts and intersecting passages.
C.D. Cullingford (1951). SVCC 1968. Extended by GOCAF and GSS in 1987.