Mokoia Island is located in Lake Rotorua in New Zealand. It has an area of 1.35 square kilometres. The 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 kumara on it.