G2 is accessible from this parking spot, same as G3. To reach the trailhead, walk about 100 meters further along the road to a  blue gate on your right; enter the forest here. The trail is obvious, and the sectors are well sign-posted.

After about 5 min, you come to an intersection; straight is G3, and to the right is Vale Zen (which is in G3) as well as the G2 sectors of Rock Master, PCC, and Coliseu.