Orakei Korako (also known as 'The Hidden Valley') is a highly active geothermal area situated in the Taupo Volcanic Zone on the Waikato River at Lake Ohakuri, which is part of the hydro-electric power scheme. The formation of the lake raised the Waikato River at Orakei Korako by 18m, flooding more than 250 hot springs and geysers. Even with two thirds of the original geothermal area covered by the artificial lake, Orakei Korako is still New Zealand's largest geyser field and one of the country's must-see natural attractions. Somewhat 'off the beaten track', the Hidden Valley lies nestled in the Taupo Volcanic Zone between Taupo and Rotorua. Orakei Korako is a mere 25 minute drive from Taupo and 45 from Rotorua, and not far from State Highway 1 and State Highway 5.