Wai-O-Tapu Thermal Wonderland, 10km south of Waimangu, is the area’s most colourful and varied geothermal site. At 10.15am daily, the 10m Lady Knox Geyser is ignominiously induced to perform by a staff member who pours a soapy surfactant into the vent. If you miss the geyser your ticket allows you to come back next morning.
Everyone then drives 1km to the main site where an hour-long walking loop wends its way through a series of small lakes which have taken on the tints of the minerals dissolved in them – yellow from sulphur, purple from manganese, green from arsenic and so on. The gurgling and growling black mud of the Devil’s Ink-Pots and a series of hissing and rumbling craters pale beside the ever-changing rainbow colours of the Artist’s Palette pools and the gorgeous, effervescent Champagne Pool, a circular bottle-green cauldron wreathed in swirling steam and fringed by a burnt-orange shelf. The waters of the Champagne Pool froth over The Terraces, a rippled accretion of lime silicate that glistens in the sunlight.
As you drive back to the main road, follow a short detour to a huge and active boiling mud pool which plops away merrily, forming lovely concentric patterns.