We visited on 4th August 2002, and had trouble finding the stone because it was just over the edge of our map!
When we got there we parked at the gate near the stone, under the watchful gaze of a police officer wearing fluorescents. He was directing traffic to some sort of equestrian show on the other side of the road. We half expected to be arrested for trespass, or climbing over a gate without due care and attention, but rather disappointingly he just stood there looking bored.
I don’t think there is a footpath to the stone, but I guess we have the ‘right to roam’ there. I’ll have to read up on this and find out how the Law stands on this sort of thing.