In reply to pasbury:
> Then why is the intransigence of the estate owners often cited as the reason why we can't climb on these splendid cliffs.
> Where does the Gloucestershire Wildlife Trust reserve begin?
All guidebooks since the 1970s have made clear that the ban on climbing on Pen Moel land (the Forbidden Wall and the smaller cliffs just downstream) is due both to the owners' wishes and to those of the GWT (supported by Natural England and its predecessors over the years).
As to your second question, my understanding has been that, though the GWT (now) own most of the Wintour's Leap land, they have only (but actively) managed the Pen Moel woodlands as part of the Reserve. Climbers' adherence to the ban has been a condition (variously formal and informal over the last 40 years) of access to the remainder of of the Wintour's crags.
I do not know how things stand now with regard to sale of the estate. Some land has already been sold and the remainder appears to be being parcelled. My inference from the phrase 'western cliff-top boundary' was that the wood and cliff land either had already been or was perhaps being subject to alternative arrangements.
What is certain is that, whoever finally gets (or has got) to own the Forbidden Wall, any forays onto it would cause a major crisis over access to Wintour's and Ban-y-gor (as if things were't difficult enough already). Please don't risk it.