Symmetrial cone of a volcano (Mt Ngauruhoe) at Tongariro National Park, New Zealand. This is the largest and most active volcano of the Tongariro group, part of the Pacific Ring of Fire.

Ngauruhoe volcano; region of volcanic activity. Volcanic activity in the zone started about 2 million years ago and continues today. This is the largest and most active volcano of the Tongariro group. Traditionally Ngauruhoe has erupted at least every nine years, although the last eruption was in 1975.