View from Mount Ngongotaha at Lake Rotorua with Mokoia Island, New Zealand
Lake Rotorua is the second largest lake in the North Island of New Zealand by surface area, and covers 79,8 square kilometres (30,8 sq mi). With a mean depth of only 10 metres (33 feet) it is considerably smaller than nearby Lake Tarawera in terms of volume of water. It is located in the Bay of Plenty region. The city of Rotorua is sited on its southern shore, and the town of Ngongotaha is at the western edge of the lake. The lake was formed from the crater of a large volcano in the Taupo Volcanic Zone. Its last major eruption was about 240.000 years ago. After the eruption,
the magma chamber underneath the volcano collapsed. The circular depression left behind is the Rotorua Caldera, which is the site of the lake.
Several other lakes of volcanic origin are located nearby to the east, around the base of the active volcano Mount Tarawera.
Mokoia Island, close to the centre of the lake, is a rhyolite lava dome rising to 180 metres above the lake surface. It is probably New Zealand's best-known lake island, and is closely associated with one of the best-known Māori legends, that of Hinemoa and Tutanekai. Is said that Hinemoa swam across the lake to her lover Tutanekai who lived on Mokoia Island. Mokoia Island is privately owned by local Māori iwi, who run it in conjunction with the New Zealand Department of Conservation. It is a bird sanctuary and access is limited to tour parties only. It is home to several rare species, including the kokako, the kiwi, and a breeding population of the endangered Saddleback.