Lying 50 km north of Tauranga, Mayor Island is the smallest caldera volcano in New Zealand.
Mayor Island (Tūhua) is the emergent summit of a caldera volcano roughly 750 m high and 15 km across. The island is dominated by the 3 km wide caldera collapse crater and contains numerous vents. At least 52 eruptions have been recorded from the island over the last 130,000 years.