Where do you find bamboo in lost in blue 3

in the beach where you find James, there should be a huge rock that block the way in the upper part of the map. bring James with you (if you are James, bring sam(Eric) with you). after you push it, you will be able to jump across the ledge. and there you are, in the bamboo grove area. in the map, there should be a big circle land. it's the bamboo grove!