Grafton Volcano

Grafton Volcano is a buried volcano in Auckland with an explosion crater about 600 meters across that contains a solidified lava lake. The lake reaches depths of at least 50 meters below the surface and now serves as a significant groundwater reservoir for the area.

This volcano formed roughly 100,000 years ago, making it older than the nearby Pukekawa Volcano. Scientists only discovered it in 2010 when boreholes and building excavations revealed its structure beneath the city.

Today the site is known mainly through Outhwaite Park, where old oak trees and maintained green spaces offer a place for locals to spend time. The park landscape sits on top of the crater and shapes how this neighborhood looks and feels.

The site sits near Auckland Hospital and is easy to reach by foot through the city's existing paths and parks. Its straightforward location makes it a good spot to visit while exploring central Auckland without needing to travel far.

The volcano has two separate vents positioned in different places: one sits within Outhwaite Park and the other at the hospital's eastern end. These two openings show just how complex the geology of this underground system truly is.