Yellowstone National Park

Yellowstone is the world's first national park and still unrivaled in geothermal spectacle, with thousands of geothermal features including Old Faithful. Spanning nearly 8,983 sq km across Wyoming, Idaho, and Montana, it sits atop a supervolcano and hosts more than half of Earth's geysers. Its roughly 4.5 million annual visitors can see the largest free-roaming bison herd in North America, alongside wolves, grizzly bears, and wolverines.