The Green Belt was supposedly caused by the Kanohi Mask of Life. The entrance to the Chamber of Life is somewhere in the green belt. The Matoran Village in it held another secret: the entrance to the Stone Cord that led to Mahri Nui.
Reidak once pursuited a Le-Matoran down it in the Piraka/Toa Inika Animations, then Thok captured the same Le Matoran before he discovered the chamber that led to the Mask of Life. It was most likely destroyed when Mata Nui rose from the sea.
| Fire Regions: Mt. Valmai • Lake of Lava • Chamber of Life • Lava Reservoirs|
Water Regions: The Cape of No Hope • Lagoon Entrance • Mahri Nui (Formerly) • Voya Nui Bay
Village Regions: Matoran Stronghold • Matoran Village • The Jungle Sanctuary • Canyon Fortress
Piraka Regions: Piraka Stronghold • The Chamber of Truth • Piraka Outpost
Ignika Chambers: Staircase to the Ignika • The Zone of Nightmares • The Chamber of Death • Umbra and Protodax's Chamber • Lava Chamber Gate
Other Regions: Ring of Ice • Cavern of Historical Records • Desert of Sorrows • The Green Belt
Lake of Protodermis • Nui Caves • Stone Cord (Destroyed)