, Northern Outcrop - East (Morlais to Abergavenny)
map using leaflet map:
In Quimps Quarry on the North side of Gilwern Hill above Twyn Wenallt. Best approached from Pwll Du, Blaenavon.
The rift entrance leads to a single passage, 180m long which ended in a clay fill at Gritstone / Limestone interface until this passed via the Wind Tunnel into the 20x30m, sloping, 1 to 3m high, Queen of Hearts chamber where no limestone is to be seen.
SWCC 1951; CwmbranCC 1994, 1997
Recorded roost of Greater Horseshoe Bat
SSSI: 0380 Gilwern Hill (Mixed)
Descent 140 (Queen of Hearts chamber)
Adrian Fawcett, The Queen of Hearts, Descent 140 (1998) p.35
Adrian Fawcett, Exploration in Ogof Dwy Sir, CwmbranCC Jnl 23 (1998) pp.7-9