Mount Saint John, Ancient volcano in Epsom, New Zealand

Mount Saint John is a scoria cone in Epsom, Auckland, rising 126 metres above sea level. Its crater is about 125 metres wide and 20 metres deep, and the cone is mantled in ash from Te Tatua-a-Riukiuta. The summit holds a water reservoir buried under the eastern crater rim.

The volcano formed over 28,500 years ago with its scoria cone subsequently blanketed by ash from nearby Te Tatua-a-Riukiuta eruption. This ancient volcanic activity helped shape Auckland's geological landscape.

The Māori name Te Kōpuke reflects the mountain's importance as a fortified settlement, where visitors can still observe the remains of storage pits and defensive earthworks.

Mount Saint John is reached from Market Road and Mount Saint John Avenue, where tracks lead up to the crater rim. The summit holds a water reservoir buried under the eastern rim, so the crater floor is not open ground. Grass paths become muddy and slippery after rain; sturdy shoes help.

The lava that flowed from Mount Saint John ran west down an old stream valley and formed Meola Reef in the Waitematā Harbour. Maungawhau / Mount Eden later erupted through this same flow, so the two volcanoes share a geological link.