Crystals are an amazing organic phenomena (not to mention their supposed healing powers). Not only do they come in all the colors of the rainbow and different shapes and textures, they form naturally through the chemical reactions of different minerals in the earth. As crystals form underground, they're hidden treasures until someone finds them. And that's what happened when someone in southern Spain when stumbled across the largest crystal cave - or geode - in the world. Called the Pulpí Geode, this 390-cubic-foot crystal room is straight out of a fairy tale book.