What is the largest hot spring in the world by volume?

Frying Pan Lake is the largest hot spring in the world by volume.

It lies in Echo Crater in New Zealand’s Waimangu Volcanic Rift Valley. The acidic lake covers about 38,000 square metres and holds roughly 200,000 cubic metres of hot water, making it far larger by volume than the famous tourist springs often proposed as alternatives.

The landscape developed through volcanic activity. The 1886 eruption of Mount Tarawera opened a long volcanic rift, while a major eruption in Echo Crater on April 1, 1917, enlarged the basin. The crater then filled with hot spring water, reaching its present form by mid-1918.

Frying Pan Lake can look as though it is boiling, but much of the bubbling comes from carbon dioxide and hydrogen sulfide gases. Its average temperature is about 55°C, and its water is strongly acidic, with an average pH near 3.8. Grand Prismatic Spring is more colorful and widely photographed, but it is not the world’s largest hot spring by volume.