The tropical island of Mata Nui is home to the Matoran and their sub-races. The nearest other known landmass is the Kentoku Archipelago, far to the east. It was named after the Matoran deity Mata Nui, in the belief they were led to this paradise by his benevolence.
The island is tropical in climate, but contains six oddly well-defined 'biomes': the six Wahi. The southern half of Mata Nui is covered mostly in Le-Wahi's expansive jungle, with its southernmost points being what remains of the Kumu Islets. Le-Wahi is bordered to the north by the Mangai Volcano and its lava flows, which make up Ta-Wahi. North of Ta-Wahi lie the grasslands and bay of Ga-Wahi and the mountains and glaciers of Ko-Wahi, to the east and west respectively. Further north are found the vast desert of Po-Wahi at the island's northernmost expanse, and Onu-Wahi's barren terrain to its west.
The island is surrounded by seemingly infinite seas stretching out to the horizon, which are aptly known as the Endless Ocean.