Lady Knox Geyser is a famous geyser located in Wai-O-Tapu Thermal Wonderland in New Zealand. It erupts daily, typically around 10:15 AM, reaching heights of up to 20 meters (65 feet). The geyser was named after Lady Frances Knox, the daughter of a former governor of New Zealand. The eruption is triggered by the addition of soap, which reduces the surface tension of the water. This allows the built-up pressure to release, resulting in a spectacular display of hot water and steam. Lady Knox Geyser is a popular attraction for tourists visiting the geothermal area.