well.. Sort of, (a Day Late)
Scrag End. The Lost levels of Rainbow, snipped off below Golgotha. Best accessed by entering Twll Mawr and foraging around the base of Running Scared for the boulder squeeze into the rear entrance of Scrag End, This Was Joe Browns original passage into Twll Mawr on his foraging, before bits dropped off.
All These levels are unclimbed (or unclaimed) and this particular wall seems to lack seepage, gets the sun, has an open aspect and a view. What it doesn't yet have is bolts.