The Devil’s Bath at Wai-O-Tapu geothermal area

This pool in Rotorua’s Wai-O-Tapu area gets its colour from a combination of hydrogen sulfide gases and ferrous (iron) salts. Rotorua, nicknamed ‘Sulfur City’, has sulfur deposits in many of its geothermal fields. The city is also known for its hydrogen sulfide smell.

Why do you think the pool has been nicknamed the Devil’s Bath?