In reply to Tony the Blade:
I'm not sure what the access situation is like, delicate possibly, but I did meet the landowner (I think) who lives in the farmhouse very close by when I went to take a look a couple of winters ago and he seemed to be a thoroughly nice chap.
It is likely to be rather wet though, and green, and a tad muddy. Not ideal probably.
How about Ladybower Quarry? Much bigger and more impressive, very unlikely that you'll find anyone climbing there. (And even if there are, they'll probably only be interested in The Rat.)