JUST A GUESS! I can possably see 2 arrows, = Divided? Big X over 2 smaller ones. X = 10 over 2 other X's. = 10 times 10 = 100 feet. 0r ten times 20 = 200 feet or some measure. So I would go out each side as the arrows show for 1 and 2 hundred feet and check with M/D. Also check the 2 sides they don't point, just in case that was a secret way that was ment to go. ( Go 1 or 2 hundred feet from stone?) My guess! Might be worth a try. If I've found something for you, you could send me a dime, Good luck!