Not sure if it's been mentioned, but:
http://www.themodernantiquarian.com/site/332/blakey_topping.html
And then there is this, we found it by taking a lane from Grosmont, the stones (with pennies stuck in the cracks of the stone) are just off the road..
http://www.themodernantiquarian.com/site/281/high_bridestones.html