I have 20 standing stones found in my stats, which I thought was really weird. What's even weirder is I remember getting the achievement when I ran by the first three stones you come to at the beginning of the game. Obviously I had already discovered them. My guess is that every time you go near a standing stone it ups your discovered stones count, even if you have already discovered it. El Duderino 22:14, 19 November 2011 (UTC)

You appear to right. I had 11 standing stones in my stats when I knew that I had at least 5 more to find, not 2. I fast-traveled to the Guardian Stones to test your idea, and it worked. Got the achievement, and my stats now say I have discovered 14 standing stones.76.181.75.250 22:26, 19 November 2011 (UTC)