Maungakiekie / One Tree Hill is a 182-metre (597 ft) volcanic peak in Auckland, New Zealand. It is an important memorial place for both Māori and other New Zealanders. The suburb around the base of the hill is also called One Tree Hill; it is surrounded by the suburbs of Royal Oak to the west, and clockwise, Epsom, Greenlane, Oranga, and Onehunga. The summit provides views across the Auckland area, and allows visitors to see both of Auckland's harbours.
The hill's scoria cones were erupted from three craters – one is intact and two have been breached by lava flows that rafted away part of the side of the scoria cone. Lava flows went in all directions, many towards Onehunga, covering an area of 20 square kilometres (7.7 sq mi), making it the second largest (in area covered) of the Auckland volcanic field, behind Rangitoto Island. The age of eruption is currently unknown, but it is older than 28,500 years as it has a mantling of volcanic ash erupted at that time from Te Tātua-a-Riukiuta volcano.