The Grand Prismatic Spring at Yellowstone National Park, Wyoming. Yellowstone contains half of all the world's known geothermal features, with more than 10,000 examples. It also has the world's largest concentration of geysers - more than 300 geysers, or two thirds of all those on the planet. According to recent studies, there is a Super Volcano under the entire park. Aerial image (photographed from a plane).