Metru Nui
The city beneath Mata Nui functions as the Great Spirit's brain, housing the Matoran whose labor keeps the god alive.

MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui is the City of Legends, the metropolis that is the literal brain of the Great Spirit Mata NuiMata NuiBuilt by the Great Beings to restore Spherus Magna, Mata Nui sustained an entire civilisation inside his body, was deposed by Teridax, and reclaimed his purpose as a mortal on Bara Magna. itself. Hidden beneath the island's surface in the middle of the Silver Sea, this isn't some small settlement. It's a sprawling urban center spanning 47.6 kio in length and 24 kio in width, divided into six elemental districts, each a marvel of MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. engineering. When the MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. of Mata NuiMata NuiBuilt by the Great Beings to restore Spherus Magna, Mata Nui sustained an entire civilisation inside his body, was deposed by Teridax, and reclaimed his purpose as a mortal on Bara Magna. faced catastrophe on their island, they returned here. What had been legend became home.
The Brain Beneath#

MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui is far more than a city. It's a physical embodiment of the Great Spirit's mind. The MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. who lived there weren't simply inhabitants. They were workers maintaining the fundamental operations of a god-like being. If they stopped their labor, if the city fell silent, Mata NuiMata Nui (Location)An island created by accident on the Great Spirit's face, home to the Matoran for a thousand years. would grow ill. Eventually he would die.
This is what makes MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui's geography so specific. Six districts, each tied to one of the six main elements: Ta-MetruTa-MetruThe fire district where Ta-Matoran perfected their craft and powered Metru Nui's industry for thousands of years. for fire, Ga-MetruGa-MetruGa-Metru is a district of Metru Nui, home to the Ga-Matoran and the Bordakh. for water, Le-MetruLe-MetruThe teal district where Le-Matoran managed everything that moved through Metru Nui, from chutes to airships. for air, Onu-MetruOnu-MetruThe deep archive-city that made mining and historical records preservation the beating heart of Metru Nui. for earth, Po-MetruPo-MetruMetru Nui's Stone District, home to carvers whose work defined the city and site of an ancient conflict that threatened to divide it. for stone, and Ko-MetruKo-MetruKo-Metru was Metru Nui's frozen intellectual quarter, home to the scholarly Ko-Matoran race. for ice. Each district housed MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. workers suited to that element, each performing specialized tasks that kept the larger machine running. The city was purpose-built, every street and structure a component in a system.
The ColiseumThe ColiseumCentral tower of Metru Nui, serving as government seat, sporting arena, and, during Teridax's masquerade, a prison for the city's Matoran population. sat at the city's heart, ruling over all six districts with an iron fist. That's where the VahkiVahkiMetru Nui's mechanical law enforcement squads, designed to maintain rigid order but ultimately undermined by chaos beyond their programming. enforcer units patrolled, policing the MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. population. Order was essential. Chaos meant the brain malfunctioned.
The Return#
For thousands of years, MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui existed only in legend. The MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. on the surface islands of Mata NuiMata Nui (Location)An island created by accident on the Great Spirit's face, home to the Matoran for a thousand years. didn't live in this hidden city. They lived topside, in their own settlements, seemingly unaware of the sprawling metropolis beneath their feet.
Then came the Great Disruption. The surface islands failed. The MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. couldn't survive there anymore. Some were transported by the Order of Mata NuiThe Order of Mata NuiThe covert organization founded by Helryx to serve the Great Spirit directly, operating in concealment from a fortress on Daxia and waging the open war against the Brotherhood of Makuta that decided the fate of the universe.. Others fled. Regardless, they were funneled into MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui, turning a city of legend into a refugee center almost overnight. A thousand MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. arrived to find a city they'd only heard about in stories, now their only option for survival.
The irony cuts deep. They'd come to the hidden brain of Mata NuiMata NuiBuilt by the Great Beings to restore Spherus Magna, Mata Nui sustained an entire civilisation inside his body, was deposed by Teridax, and reclaimed his purpose as a mortal on Bara Magna. expecting sanctuary. Instead, they walked into a city where TeridaxTeridaxTeridax orchestrated a thousand-year scheme that ended with him occupying the Great Spirit Robot itself before his death on Bara Magna.'s shadow loomed larger than ever, where the VahkiVahkiMetru Nui's mechanical law enforcement squads, designed to maintain rigid order but ultimately undermined by chaos beyond their programming. watched every movement, where freedom was a commodity none of them could afford.
Six Districts, One Purpose#
Each district handled a specific function. Ta-MetruTa-MetruThe fire district where Ta-Matoran perfected their craft and powered Metru Nui's industry for thousands of years.'s forges produced metal and weapons. Water systems fell to Ga-MetruGa-MetruGa-Metru is a district of Metru Nui, home to the Ga-Matoran and the Bordakh.. Transportation and the Chute network were Le-MetruLe-MetruThe teal district where Le-Matoran managed everything that moved through Metru Nui, from chutes to airships.'s domain. Onu-MetruOnu-MetruThe deep archive-city that made mining and historical records preservation the beating heart of Metru Nui. extracted resources from below the city. Po-MetruPo-MetruMetru Nui's Stone District, home to carvers whose work defined the city and site of an ancient conflict that threatened to divide it. shaped and refined raw materials. Ko-MetruKo-MetruKo-Metru was Metru Nui's frozen intellectual quarter, home to the scholarly Ko-Matoran race. held knowledge and archives. Together, they kept the entire machine alive.
Walking through MetruMetruIn the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it. Nui was walking through six different cities stitched together. Each had its own character, its own industry, its own MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. population. The transportation system that connected them, with flying Chute systems and roads between districts, was a feat most MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. never took for granted.
The ColiseumThe ColiseumCentral tower of Metru Nui, serving as government seat, sporting arena, and, during Teridax's masquerade, a prison for the city's Matoran population. ruled over all of it, but the districts had autonomy in how they ran their specific operations. That autonomy was both their strength and their fatal vulnerability when TeridaxTeridaxTeridax orchestrated a thousand-year scheme that ended with him occupying the Great Spirit Robot itself before his death on Bara Magna.'s plans came to fruition.
Compiled from primary sources by Lore Fortress editorial. Reviewed by Joe Garratt, Editor-in-Chief.
Sources
- BookBIONICLE Metru Nui Arc Novels (2004-2005) — Metru Nui series featuring the Toa Metru and the city's role in the Matoran Universe.
- ComicBIONICLE Official Comics — Comic series spanning the Metru Nui storyline and district narratives.
- WikiBS01 Wiki: Metru Nui — Bionicle Sector 01 hub for Metru Nui lore and locations.
- SerialGreg Farshtey Official Serials — Continuation and clarification of Metru Nui canon via official Bionicle canon keeper.
Spotted a factual error or a primary source we missed? Email a correction. Every flagged claim gets reviewed.
Related entries
Metru
In the Matoran language a metru was a single district of Metru Nui; the city was divided into six such districts, one for each element, and the term covered both the place and the elemental community that lived in it.
Ta-Metru
The fire district where Ta-Matoran perfected their craft and powered Metru Nui's industry for thousands of years.
Onu-Metru
The deep archive-city that made mining and historical records preservation the beating heart of Metru Nui.
Ko-Metru
Ko-Metru was Metru Nui's frozen intellectual quarter, home to the scholarly Ko-Matoran race.
Po-Metru
Metru Nui's Stone District, home to carvers whose work defined the city and site of an ancient conflict that threatened to divide it.
Le-Metru
The teal district where Le-Matoran managed everything that moved through Metru Nui, from chutes to airships.
Mentioned in563 entries
"Kratana"
A small mask-attaching organism resembling a cross between a Krana and a Kraata, created by the Order of Mata Nui, used to project visions of the past and future onto whoever wore one.
Aero Slicers
The Toa Tools wielded by Toa Metru Matau, capable of channeling Air, serving as melee blades, and catching wind to permit limited gliding flight.
Ahkmou
A Po-Matoran carver of Metru Nui, one of the six Great Disk holders, who collaborated with Makuta Teridax and later imposed false Turaga rule during Teridax's reign.
Air
One of the six primary elements of the Matoran Universe, carried by the Le- prefix across its bearers and most prominently wielded by the Toa of Air Lewa, Matau, and Lesovikk.
Aiyetoro
Aiyetoro was an Onu-Matoran of Metru Nui who became a miner in Onu-Koro on Mata Nui, one of the laborers who dug for protodermis and lightstones beneath the island.
Akilini
Akilini was the principal sport of Metru Nui, played with Kanoka disks on the arena floor of the Coliseum and serving as both civic spectacle and the means by which the worth of a freshly forged disk was tested before mask-making.
Ally: Po-Matoran of Metru Nui
Ally was a Po-Matoran native to Metru Nui who helped build Po-Koro on the island of Mata Nui, served in the Po-Koro Guard, and made a final stand against the Bohrok before the swarms were stopped.
Amaya
Amaya was a Ga-Matoran native to Metru Nui who taught Vhisola before the Great Cataclysm and later served as the Flax Maker of Ga-Koro on the island of Mata Nui.
Amaya's Hut
Amaya's Hut was a small driftwood dwelling in Ga-Koro that housed a Flax Weaver, a jellyfish lamp, and the quiet labor of Matoran daily life.
Amaya's Jetty
A small lily-pad jetty extending from Amaya's Hut at the eastern edge of Ga-Koro, marked by three Bamboo Poles and a Ruki poem.
Archives Mole
Small, harmless burrowing Rahi engineered by the Makuta, originally native to Po-Metru and forced into the shadowy recesses of the Onu-Metru Archives, where their cooperative behaviour built living ladders and bridges through the lower levels.
Artakha
Artakha was the master craftsman of the Matoran Universe, ruler of a hidden island, and the forger of the Toa Mata, the Avohkii, and the Kraahkan.
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