These are the boiling mud pots of Rotorua, a city in New Zealand known for its Māori culture and geothermal activity. It is the only city in the world that is located on an active geothermal field.

Geothermal activity, from the Greek geo meaning earth and therme meaning heat, seethes from cracks in the streets, steams from backyard hot pools, bursts from geysers throughout the area, and bubbles from cauldron-like mud pools.

In this video by , watch as the sulfurous steam belches up through the thick liquid, sending drops of volcanic ash and clay splattering and plopping everywhere. It smells of H2S (Hydrogen Sulphide) there; imagine the smell of rotten eggs. To hear the boiling, listen to these mudpots in Yellowstone.

Related watching: geysers.