The focal setting of BIONICLE's story from 2001 to 2003. It is an island paradise named after the Great Spirit, Mata Nui, divided into 6 distinct environmental regions or "Wahi". At the end of the 2003 story, it's revealed that the lost city of Metru Nui sat directly below it. And even later, it was revealed that the island served as camouflage for the face of the Great Spirit Robot.
The 6 Wahi are:
- Ta-Wahi - The region of Fire and location of Ta-Koro which is situated in the Lake of Fire. It is home to the Ta-Matoran. The Mangai Volcano and Charred Jungle are located here.
- Le-Wahi - The region of Air and the location of Le-Koro. It is home to the Le-Matoran as well as most of the island's forest and jungles. The islands largest lakes, Lake Pala and Lake Kanae are also located here.
- Ko-Wahi - The region of Ice and location of Ko-Koro. Home of the Ko-Matoran, it makes up the islands glaciers and snowy mountain range.
- Ga-Wahi - The region of Water and location of Ga-Koro which is situated in Naho Bay. The home of the Ga-Matroran.
- Onu-Koro - The region of Earth and the location of Onu-Koro. The Onu-Matoran who live their make their homes underground.
- Po-Wahi - The region of Stone and location of Po-Koro. The Po-Matoran live here, and is the location of Tiro Canyon and Motara Desert.