The only place I found after a bit of a hunt last year was here -
http://maps.google.co.uk/maps?f=q&s...6682,-1.547994&spn=0.002211,0.006866&t=h&z=18 - not really North West, but the best I could find after searching flickr and here. There is a thread somewhere on here with more maps etc, but the link above should take you to where I got these shots from:
Also noticed other fields around the area but this had the best access, no official footpath that I could make out, but visable tracks where others had been.
Hope that helps.