Lake Pupuke is one of the oldest known features of the Auckland volcanic field, erupting an estimated 193,200 years ago.
Lake Pupuke remains a lake because, unlike the other vents, its eruptions produced substantial lava flows; water can thus escape through cracks in the lava reaching under the crater wall, creating a series of freshwater springs along the beaches between Takapuna and Milford.
The lava flow at the end of Takapuna Beach enveloped a kauri forest, producing an internationally significant collection of tree moulds, which has been called "New Zealand’s only example of a fossil forest preserved in a lava flow" and which "ranks among the best examples in the world.
"[5] Some moulds have escaped burial by the boat ramp and car park built on top of the lava, and can be viewed at low tide.
[6] A small scoria cone existed to the west of Lake Pupuke, which was quarried during European settlement.
[7] In 1894, a pump house was built on the shore of the lake to supply fresh water to the local area.
[7] A Māori myth surrounding the lake tells of a tupua couple, children of the fire gods.
[22] Lake Pupuke is identified as a "high risk" area in the event of a tsunami, and a high-tech phone alert system was developed for North Shore residents in case of an emergency.