What is "otuataua"

Otuataua, located in the suburb of Mangere, is one of the volcanoes in the Auckland Volcanic Field. The scoria cone reached 64 m above sea level but was mostly quarried away, leaving the base of the cone with a large depression in it. It was the site of a pā, and is part of the Otuataua Stonefields reserve, which features Māori stone garden mounds and European dry-stone walls.