Upper Geyser Basin in Yellowstone National Park, Wyoming, USA

Where fire and water meet. Upper Geyser Basin, Yellowstone, USA

The world’s highest concentration of geysers and hydrothermal springs are found in this corner of Yellowstone National Park in the western US. Here in Upper Geyser Basin, you’ll find perhaps the most famous of them all: Old Faithful, along with the tallest predictable geyser (Grand Geyser) and the most voluminous geyser (Giant Geyser). Yellowstone contains more than 10,000 hydrothermal features, including hot springs, mudpots, fumaroles (which release hot gases) and hundreds of geysers.