Just been having another look at google maps, this is where the Whittle drift entrance was I believe:
https://maps.google.co.uk/maps/ms?ms...00201,0.005659
Bizarrely there is a 'black hole' here:
http://maps.google.co.uk/maps?f=q&so...00283&t=k&z=19
which would not be far from the other shaft entrance? Surely that's something that just 'looks like' a hole in the ground????