When I went hunting for Knocks North stone circle I was told it was 'ruined', so when I could not find an easy route to it I didn't go out of my way and I've never bothered going back to see it. From the road 150m away I could see the tops of two stones over a hedge and that was it.
I'll have to go back now, though. It's a cracker!
http://www.themodernantiquarian.com/post/67423/images/knocks_north.html?stream=latest
Thanks Gordon!