The Mangai Volcano was the great volcano of Mata Nui. As of mid-story year 2007, molten lava still flowed from this site, feeding the lava farms of Ta-Wahi.
Streams of lava (molten protodermis) flowed from the Mangai Volcano.
The Mangai Volcano was located in Ta-Wahi.
The Mangai, located in Ta-Wahi, was the great volcano of Mata Nui. As was later discovered, the lava coming out of the volcano was actually molten protodermis from Ta-Metru in Metru Nui.