Every morning, a rocky grey vent called the Lady Knox Geyser spews water for a captive audience. Far from a strange local ritual, the geyser is one of the star geothermal attractions at Rotorua’s Wai-O-Tapu Thermal Wonderland. It erupts without fail—after being induced with soap—to heights of 30 to 65 feet (9 to 20 meters).The Basics
The Taupo Volcanic Zone is known for its geysers and geothermal activity, but the Lady Knox Geyser is especially unique because of the way in which it erupts: every morning, a park guide at Wai-O-Tapu Thermal Wonderland in Rotorua induces it to erupt with soap. The subsequent eruption can vary in size and length, but on a good day the geyser creates a 65-foot (20-meter) eruption that can last for up to an hour. The eruption is enhanced by stones placed around the geyser’s nozzle, and an amphitheater has been built in front of the geyser so no one in the audience misses out. The site is also full of mud pools and rugged geothermal features, so there’s more to experience once you’ve seen the geyser.
Some full-day tours of Rotorua include a Lady Knox eruption. If visiting independently, purchase tickets to see the geyser erupt at Wai-O-Tapu’s visitor center.
Things to Know Before You Go
How to Get There
- Lady Knox Geyser and the Wai-O-Tapu Thermal Wonderland are a must-see for nature lovers and first-time visitors to Rotorua.
- You’ll be doing plenty of walking outdoors at Wai-O-Tapu, so come with sturdy shoes and, depending on the weather, sunscreen or rain jackets.
- The Wai-O-Tapu Visitor Centre is home to a sunny café, a gift shop where you can pick up souvenirs and Maori carvings, and secure lockers for use during your visit.
- Lady Knox Geyser is not accessible to wheelchair users.
The Lady Knox Geyser is located in Wai-O-Tapu Thermal Wonderland, about a 20-minute drive south of Rotorua along the Thermal Explorer Highway (State Highway 5). Stop at the Wonderland Visitor Centre for directions to the geyser, where there is plenty of parking. There are also several shuttle services that run between Wai-O-Tapu and Rotorua.When to Get There
Wai-O-Tapu is open every day of the year, and the Lady Knox Geyser’s eruption is induced around 10:15am. The geyser is popular and the amphitheater can fill up quickly, so arrive 15 to 30 minutes early to guarantee seats close to the action.How Does Soap Induce an Eruption?
The soap used to induce the Lady Knox Geyser’s daily eruption reduces the surface tension of the cold water in the geyser’s upper chamber. This causes the cold water to mix with the hot water in the lower chamber, triggering the eruption. This reaction was discovered by chance in the early 1900s, when a group of prisoners tried to wash their clothes in the hot water!