|Region of Mata Nui|
|Residents||Onu-Matoran, Toa Onua, Turaga Whenua, Rahi (all formerly)|
When Mata Nui crashed onto the Aqua Magna moon, his island creating system activated, and an island was created above his face. The outer surface of the island was created by an Energized Protodermis leak. Before the Great Rescue, the Toa Metru discovered this island and began to seek out living areas for the Matoran to live. The region of Onu-Wahi was named by Toa Whenua. After completing their mission and saving the Matoran, the Onu-Matoran and Whenua, now a Turaga, built the city of Onu-Koro and inhabited it. The Great Mine was also constructed so the Matoran could excavate precious ore that was abundant in the earth. Of the duration of the Dark Time and the Great War, Onu-Wahi was subjected to many strikes by Teridax and his infected Rahi. A Vatuka captured Whenua, but he was saved by Takua who also found Vakama's Firestaff. Takua later found two Vuata Maca Crystals and a Toa Stone.
Onua's Toa Canister first arrived on Mata Nui in the Onu-Wahi region, after the Av-Matoran Takua accidentally sent out a signal beckoning the six Toa Canisters toward the island. The Toa of Earth was able to recall his name and rediscover his abilities, before he dug underground, immediately feeling at home. Onua then came across Onepu who led him to Onu-Koro.
Takua traveled into Onu-Wahi and found that a mining area was flooded by lava since the pump for draining it was broken. Helping the Onu-Matoran present, Takua surfed over the magma and fixed the machine, making the way clear for the Lightstones to be mined out of a special chamber. With the abundance of lightstones, Taipu and some Miners were able to continue and finish the Le-Koro Highway project which had been put on hiatus.
Afterward, learning of an impenetrable rock layer found in the Great Mine, Takua and a Prospector began to study it. After discovering what was a Sundial embedded on the top of the stone, Takua traveled to Ga-Koro and spoke to Nixie about the markings. Gaining a gnomon from the Astrologer, he returned to the Sundial and activated it with the gnomon and a lightstone which he shone upon it. The Sundial then opened to reveal a stairway leading to a gold mask. Later, after the Battle for Kini-Nui, Takua would discover it was a hidden entrance to Mangaia, and used it to enter the Makuta's lair and watch the Toa defeat him.
A swarm of Nuhvok entered Onu-Wahi almost immediately after they awoke from their nest. Though Onua was able to stop the creatures before any permanent damage was done, he was not able to hold back the Gahlok that flooded the Great Mine or Onu-Koro afterward. Onepu and Taipu directed the Onu-Matoran toward the surface when the Gahlok began to flood Onu-Wahi. As Nuparu headed toward the exit, however, the tides reached the last three Matoran and knocked them in a separate cavern which was then sealed with stone. The three conversed after finding a nonoperational Gahlok and began to dig their way out. Nuparu decided to work on the mechanical Bohrok however after having an idea. The Engineer then created the Boxor and used it to dig out of the cavern. Confronting some Gahlok, the three drove off the creatures with the new invention.
During the Bohrok-Kal's strike, Toa Nuva Onua and Whenua ventured deep into the Onu-Wahi region to find a hidden Kaukau Nuva. The two would find their way down into a heated cavern which held two Manas fighting against each other. Using lessons he had learned from the Turaga, the elementally weakened Toa dug deep into the earth and found a pocket of lava. This caught the attention of the heat loving Manas and the Kofo-Jaga nearby which then began to fight over the magma. Onua was able to slip past and acquire the Kanohi in the back of the cavern. He and Whenua then escaped the region and headed home.
While searching for the seventh Toa, being guided by the Avohkii, Takua and Jaller traveled into the Onu-Koro Highway. Playing with some plants, Takua was separated from Jaller and his crab Pewku and came into contact with Teridax. Threatening him in the manifestation of a shadow, Teridax promised to leave his friends and villagers alone if given the mask. However, Takua refused and ran from him finding Jaller shortly after. The Av-Matoran was frightened though by Teridax and also decided not to journey with Jaller any longer. The two then parted on angry terms.
After the Toa Nuva reawakened the Bohrok swarms, Onu-Wahi was cleared of all its tunnels and structures. When Mata Nui finally awakened, the entire island was obliterated.
Onu-Wahi was mainly located underground, tunnels built by the Onu-Matoran leading the area to different parts of the island. The area was comprised mainly of caves and caverns beneath the ground, and Onu-Koro is also located here. Although Onu-Wahi did include surface areas, very little of the surface was ever developed.
- Great Mine
- Papa Nihu Reef
Onu-Kini was the Temple of Earth.
The Onu-Matoran were the primary Matoran residents of Onu-Wahi. They resided in the village of Onu-Koro, and performed day-to-day activities which mainly consists of mining or digging.
Onu-Wahi was home to Rahi species, mostly with genetic adaption to aid in underground life. Among them were:
- Mata Nui Saga (Not Mentioned by Name)
- BIONICLE Chronicles 1: Tale of the Toa
- BIONICLE Chronicles 2: Beware the Bohrok
- BIONICLE Chronicles 4: Tales of the Masks
- BIONICLE: Encyclopedia (Mentioned Only)
- BIONICLE: Encyclopedia Updated (Mentioned Only)
- BIONICLE: Quest for the Toa
- Toa Mata Promo Animations
- Mata Nui Online Game
- BIONICLE: Quest for the Masks (Non-canonical Appearance)
- BIONICLE: The Legend of Mata Nui (Non-canonical Appearance)
- Toa Mata Nestlé Promo CD
- Toa Mata Platform Game
- BIONICLE: Matoran Adventures (Non-canonical Appearance)
- Toa Nuva Promo Animations
- Mata Nui Online Game II: The Final Chronicle
|Po-Wahi << Onu-Wahi - Onu-Koro >> Ko-Wahi|
| Papa Nihu Reef | Cavern of Light | Onu-Koro Highway | Le-Koro Highway|
Great Mine (Sundial Entrance) | Marn Tunnels | Temple of Prosperity
|Ta-Wahi (Ta-Koro) | Ga-Wahi (Ga-Koro) | Le-Wahi - (Le-Koro) | Po-Wahi (Po-Koro) | Onu-Wahi (Onu-Koro) | Ko-Wahi (Ko-Koro) | Kini-Nui|
|Solis Magna||Spherus Magna | Red Star|
|Metru Nui (Maze of Shadows) | Karzahni | Zakaz | Xia (The Mountain) | Northern Continent (Tren Krom Peninsula) | Artakha | Stelt | Odina | Southern Continent (Voya Nui) | Karda Nui | The Pit | Destral | Nynrah | Tren Krom's Island | Visorak | Daxia | Southern Islands (Artidax)|
|Pocket Dimensions||Field of Shadows | City of Silver|
|Alternate Universes||The Melding | Spherus Magna | Toa Empire | The Kingdom|
|Characters | Sapient Species | Locations | Flora | Fauna | Objects | Powers | Vehicles | Society | Events|
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