Into the Lost Crystal Caves
NGC travels into one of the world's greatest natural wonders - a colossal crystal cave dubbed Superman's stronghold, with stunning crystals measuring up to 36 feet in length and weighing 55 tons. A group of experts travel into the underground, braving temperatures that might kill a human after only 15 minutes. They'll defy physical limitations in order to explore a chasm that may lead to another, possibly more stunning, crystal cave.