Maya - activating the crystal. 

You are standing at the foot of the stairs, looking back toward the Jaguar's pyramid. Hold the crystal up toward the tree and pyramid until the lines turn red. They do not have to match the pattern as closely as you see in the picture here; as long as the lines are red you have found it

You can activate the crystal now, or wait until you have visited all three lands; and do all the crystal-trips together. It doesn't matter, but there is less disc-swapping if you do them while you are there the first time..