In reply to Nevis_Ben:
> I left left some gear up there last year (labelled up). Had to ab off as last pitch was undoable.
The last pitch is always doable. You don't climb up the back but out on to a chockstone, from where (unexpectedly) you can go outside the chimney. I was once climbing it and the team ahead said it was impossible, so I showed them how to do it, and we all succeeded.