Crystal Caves – Atherton Posted on March 26, 2015May 4, 2015 by Trev Another one of those local suggestions… who wouldn’t want to see the Worlds biggest Amethyst Geode. There are lots of great items in this collection including the giant geode. If you look very closely you might see what scared the kids. Atherton Tablelands - Camp Barrabadeen Cairns what a week!