Yellowstone National Park is the first National Park established in the USA. It is a large and very diverse park divided into four major sections. Each section is distinct and unique. In one of the sections located inside the volcanic caldera, there are numerous geothermal features such as geysers and hot pools. The famous Old Faithful geyser is located there as well. Yellowstone is the most interesting location for the geothermal features in the world. It is very different in the winter time. See Yellowstone National Park in Winter here.