It's in the order of which you Should've found them,
(which I always find out of order, but anywaz).
1) The one that sits on the temple
2) By the Save Sphere
3) Along the Bridge
4) By the pond
You've already said that, so be sure Your entering the Correct #'s. Go back and look again, some of the #'s look alike.
The reward for this is only a GG which Equipped you can use Confusion.
When you do get the wall to raise, walk through the area, and you'll be outside on a waterfall, keep walking down and you'll find a chest on the edge. The GG is in there. (I didn't find much use for this.)