Lake Rotorua is the second largest lake in the North Island of New Zealand by surface area, and covers 79.8 km2. With a mean depth of only 10 metres it is considerably smaller than nearby Lake Tarawera in terms of volume of water. It is located within the Rotorua Caldera in the Bay of Plenty Region.

Mokoia Island is located in Lake Rotorua in New Zealand. It has an area of 1.35 square kilometres. The uninhabited island is a rhyolite lava dome, rising to 180 metres above the lake surface. It was formed after the Rotorua caldera collapsed and rhyolitic magma was pushed through the cracks. One of the cracks was below where Mokoia island is today. The foreshores of the island have geothermal springs with hot spring water forming the Hinemoa pool, known to locals as Waikimihia. It also has very rich volcanic soil, which was why the local Māori grew kūmara on it. The stone statue of Matuatonga on the island protected the island's kūmara crop, and tohunga would bring seed kūmara to touch the statue. It was also a very good strategic location, which was why it was often fought over.