Where is the largest hot spring in the world?

The Grand Prismatic Spring, located in the Midway Geyser Basin of Yellowstone National Park, measures about 90 metres across and is the largest hot spring in the United States. Its dazzling rings of blue, green, yellow, and orange come from heat-loving microbes that thrive at different temperatures around the spring. The deep blue centre is extremely hot, while cooler edges support the vivid colours. The largest hot springs by area in the world are in New Zealand, such as the Frying Pan Lake. Yellowstone sits atop a vast volcanic hotspot that powers its geysers and springs.