Hauhungatahi is an eroded volcano at the southern end of the Taupo Volcanic Zone in New Zealand, located about WNW of Mount Ruapehu. Although relatively little-known, at Hauhungatahi is one of the highest volcanoes in New Zealand, exceeded in elevation by only Ruapehu, Taranaki/Egmont (including Fanthams Peak), and the Tongariro massif (including Ngauruhoe). The volcano is constructed atop an upfaulted block of Mesozoic marine sediments. The age of the erupted andesite lava is about 900,000 years, making Hauhungatahi more than three times as old as the neighboring Ruapehu.