Champagne Pool, Geothermal pool in Waiotapu, New Zealand.

Champagne Pool is a crater roughly 65 m across and up to 62 m deep in the Wai-O-Tapu geothermal area, holding about 50,000 m3 of siliceous fluid at 73-75 °C. Its rim is ringed by grey-white silica sinter, while orange orpiment and stibnite deposits lie just below the surface.

The basin formed roughly 900 years ago through a hydrothermal eruption and sits within the Okataina Volcanic Centre near the Reporoa caldera. This geothermal landscape has been shaped over millennia by ongoing volcanic activity typical of this region.

The pool's name comes from the continuous stream of carbon dioxide bubbles rising to the surface, compared to the beads in a flute of champagne. The escaping gas is mainly CO2, with smaller amounts of nitrogen, methane, hydrogen, hydrogen sulphide and traces of oxygen. The same gas flux keeps the water's pH steady at about 5.5.

The pool is well marked and reached via a maintained walkway equipped with handrails and viewing platforms for safe exploration. Visitors should wear sturdy shoes and be aware of hot steam rising from the water, which is especially visible on cooler days.

The water shimmers in green and orange hues created by mineral deposits and algae, while carbon dioxide bubbles continuously rise to the surface. This color display shifts depending on the angle of light and time of day, making each visit look different.