In reply to Graeme Hammond:
I agree with andy wa regarding secret crags. However regarding access please consider this, copied from UKcaving: (The DCA is the Derbyshire Caving Association)
ELDON HILL QUARRY
DCA’s website now has details of the latest developments in the access situation. Chatsworth own the Quarry and don’t want the site widely publicised at this stage, and their tenant farmer has concerns of his own regarding visitors. Natural England also have an interest as the Quarry is part of the Castleton SSSI. However, an accommodation has now been reached and anyone interested should refer to thedca.org.uk/
At the very least the Chatsworth Estate require visitors to have public liability insurance.
The quarry is in a quite dangerous state and I don't think the owners would be very happy about climbing. Probably best to keep a low profile.
Anyway lets hope for suitable cold conditions to occur again. The climbs are really quite good.