Metru Nui

Metru Nui, the City of Legends, is the subterranean island where the Matoran evolved and inhabited until Makuta took over. It is found beneath Mata Nui.

History
The city of Metru Nui was founded and built roughly a hundred thousand years ago, around the same time that the Brotherhood of Makuta and Order of Mata Nui were founded. Metru Nui's foundations were laid by the Great Beings, and the rest was built by Matoran. Since then, it has been the ecumenopolis homeland of the Matoran for millenia. Metru Nui and its troubles is the central plot of the Bionicle.

Around eighty thousand years ago, there was a civil war called the "Great Disruption." Little is known about the four-hundred-year conflict, but the Brotherhood of Makuta ended the fighting and banished the war leaders to a place known as "The Pit". The Order of Mata Nui placed an agent in the city to ward off further conflicts.

Metru Nui was definitely not devoid of conflict, however. Under the leadership and secret corruption of Turaga Dume, the Morbuzahk Plants, Vahki, The Great Cataclysm, and the Visorak swarms all destroyed the city, reducing it to rubble, a ghost of its former self. Entire chunks of the island, such as the one that would later become Voya Nui, broke free from the strain of the earthquakes. Only under the diligent protection of the Toa Metru were these things kept at bay. Makuta, under the guise of Dume, orchestrated all these events, and imprisoned the Matoran in pods.

The Toa rescued the Matoran, and placed them above ground, on the island of Mata Nui. They gave up their power to do so, and became Turaga. Metru Nui would wait until Makuta was defeated again by the Toa Mata, and later, Takanuva. After the battle over the Mask of Light, the gate to Metru Nui via Mangaia was once again opened. The Matoran made their way to their "old" home, and settled it once again. The battle against Makuta was taken to other fronts, and Metru Nui was finally safe. The peace might not last forever, however...

Environment
The city of Metru Nui is actually underground, far below the island that came to be known as Mata Nui. The Matoran living there are generally unaware of this, however, mists obscure the cavern walls (called "the Great Barrier") and give the appearance of a normal sky. The city also stands in the center of a vast "Silver Sea" of Liquid Protodermis.

District System
The population of Metru Nui was dispersed throughout six "districts", each specializing in a specific element and occupation, and the central point where many things take place.

Coliseum
The Coliseum is at the center of the city of Metru Nui, where the borders of the six districts meet. It is where sporting events such as Akilini take place, as well as being the main power station for the city. It also serves as Turaga Dume's home. When the Visorak invaded the city, they made the Coliseum their main nesting grounds.

Ta-Metru
Ta-Metru is the place where Protodermis is molded and manufactured after it is rid of its impurities in Ga-Metru. Because of all the smoke and heat from the foundries and forges, Matoran from other districts do not like to stay here long.

Ga-Metru
Ga-Metru is the center of learning in the city, where the schools and research labs are located. This is also the district where Liquid Protodermis is taken from the Silver Sea and purifed so that it could be used elsewhere, there are canals for Liquid Protodermis everywhere. Ga-Metru is very peaceful.

Le-Metru
Le-Metru is the transport hub of the city. Le-Matoran are in charge of the entire city's transport network, particularly the system of chutes that move people and things between Metru. The flurry of activity and the number of wires strung about give the district the feeling of an urban jungle and of barely controlled chaos. Le-Metru's Moto-Hub is the largest chute station in Metru Nui, as well as the administration building for chutes, where the main controls are located. There is also a Test Track, where new vehicle designs are made and tested by volunteer Matoran.

Onu-Metru
Onu-Metru is home to the Archives, an underground museum complex where Onu-Matoran archivists work hard to preserve artifacts of Metru Nui's history. The archives have actually expanded again and again, to the point where they stretch underneath the whole city. Besides just artifacts, Rahi are also kept in the Archives.

Po-Metru
Po-Metru is the most natural of all the city districts, as it is made up mainly of rocky mountains and canyons. Po-Matoran like to work outside, assembling goods and carving statues. Rahi attacks and stampedes are somewhat common in this district. Po-Metru's claim to fame is the Sculpture Fields, a large expanse where Po-Matoran work to carve giant statues much too large for any building.

Ko-Metru
Ko-Metru is known best for its Knowledge Towers, which are crystalline structures that can reach so high that their rooftops are often covered with ice. Ko-Matoran are scholars and seers who study and analyze, trying to predict the future. The district is kept incredibly cold, in order to better preserve written documents. Ko-Metru is the quietest district in the city, as Ko-Matoran hate to have their work interrupted. The mythical Rahi Keetongu also made his home in a Ko-Metru cave.

Transportation
The beings of Metru Nui moved throughout the city using "chutes", air-filled magnetically-powered tubes in a network managed by Le-Metru.

Daily Life
Most Matoran stayed in their districts, working in a specific job type. The Ta-Matoran worked using the molten protodermis to create Kanohi masks, Kanoka disks, and other tools. The Le-Matoran were in charge of the chute system, the Ga-Matoran specialized in education, and the Po-Matoran were good in architecture, sculpting, and craftsmanship. Onu-Metru ran mining and the Great Archives, a massive zoological, scientific, and historical project. Ko-Matoran would meditate in their knowledge towers, providing needed insight and philosophy. Metru Nui would run this way for a long time, into the days of its destruction.

Crime
In a city as large as Metru Nui, unsavory folk were commonplace, and so were their deeds. These are the main crimes.

Smuggling and Theft
Everything had value, stolen or not. This was exploited. Metru Nui had a vast black market, with many customers and products, ranging from counterfeit widgets to a wild rahi.

Vahki
The Matoran were protected and policed (sometimes violently) by mechanical inventions like the Vahki. This force held powers of coercion and powerful persuasion to help them deal with criminals.

Toa
Metru Nui has been protected by Toa teams throughout the ages, whether slaying legendary rahi or serving and defeating The Brotherhood of Makuta. Toa passed power down to ordinary Matoran, continuing the cycle of having venerable superheroes to defend the city. The most famous of these are the Toa Metru.

Disks
Kanoka disks were used as common weaponry for the Matoran. These disks had adaptive powers according to their numbers and elements. Unfortunately, this developed into the popular but illegal sport of Disk Dueling.

Name
Fans have translated "Metru Nui" into "Great City". This means that Ta-Metru means fire city, Ga-Metru water city, and so forth.

Appearances
Metru Nui has appeared in most Bionicle sources, since Mata Nui and its inhabitants are actually part of Metru Nui.