Frying Pan Lake (renamed Waimangu Cauldron in 1963[1] though not widely used) is the world's largest hot spring.

[2][3] It is located in the Echo Crater of the Waimangu Volcanic Rift Valley, New Zealand and its acidic water maintains a temperature of about 50 to 60 °C (122–140 °F).

[5] The most recent eruption in Echo Crater occurred on 22 February 1973, destroying the Trinity Terrace area on the south-eastern shore of Frying Pan Lake.

[8] Both lakes' water levels and overflow volumes follow a complicated rhythm that repeats itself roughly every 38 days.

[5] Frying Pan Lake is one of the first major attractions encountered along the wheelchair-friendly main Waimangu walking track.