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Ostra Nui is a pair of large islands where ToaOstra's stories take place.

Ostra Nui
Matoran Universe
26,000 square kio
In existence


10,000 years ago, a large earthquake separated Ostra Nui from the Southern Continent. A Makuta named Nozibak was still on the island when it separated and was left there, drifting on his own. Eventually, when it stopped, Nozibak used his Shadow power to create Rahi. He trained many Rahi into being his slaves, and ruled the land.

The Hanrei Chronicles[]

1,000 years ago, the Toa Hanrei heard of Ostra Nui and decided to investigate. Tohrik, the Toa of Fire, led his team, Fahro, Toa of Air, Idioni, Toa of Water, Piricos, Toa of Stone, Ourio, Toa of Earth, and Artius, Toa of Ice, to this mysterious island by boat. When they arrived, they were attacked by many Bone Bears. Lerui, a Le-Matoran that snuck onto the boat, tamed one of the Bone Bears (which he named Pakari Nui) and scared off the other Bone Bears.

Over the next thousand years, Matoran have travelled here and colonized the Northern Island.


The region of Ostra Nui is spilt into the Northern and Southern Islands. The Northern Island is where the Matoran civilized when they arrived. The Southern Island is where Nozibak and his Rahi. The only way to travel between the islands is by air as the ocean is -200 degrees Fahrenheit and highly radioactive.


Ta-Ostra is a city that is located in the south/center of the Northern Island. It is built around an inactive volcano.


One of Ta-Ostra's factories

There are many factories in Ta-Ostra, and the smoke emitted makes the sky have a constant orange tinge.

The main residents of Ta-Ostra are Ta- and Fe-Matoran.


City of Arabia-1

View of the Le-Ostran City from the air.

Le-Ostra is acity just east of Ta-Ostra. This is where the Ostra NuiAerialVehicles (ONAVs for short) are made. This is also home to the ONAV Battle Tournament Arena. ONAV Battles are where Matoran battle their ONAVs untileither one of the Matoran concedes or one of the ONAVs crashes. The city's power is not run by the main power grid, like all the other cities. It runs on wind power collected from wind tunnels in the walls of each building. The city is lined with tall buildings that many Matorans use the roofs to glide off. Half of the city is a forest, where many Matorans go to get in touch with their ancestry.

The main residents of Le-Ostra are Le-Matoran and Matoran of the Green.


Onu-Ostra is an underground city that is in the center of the Northern Island. There is a series of tunnels that

Onu ostra

One of the tunnels in Onu-Ostra

run from the Central Village through out the city. Each tunnel has mine cart tracks. These carts carry resources from all around the Island and are used to trade between cities. Onu-Ostra is the main exporter of natural Protosteel, which is used to build.

The main residents of Onu-Ostra are Onu-Matoran, Ba-Matoran and Matoran of Magnetism.


Po-Ostra is the westernmost city on the Northern Island. It often has strong, but short, gusts of sand from the desert on the east, making it hard to see. It also has a large bridge

Po ostra

View of Po-Ostra from one of the bridges

system that runs on the eastern side of the city. These bridges are used by the Matoran to travel from one place to the other. The city also has a factory that makes road vehicles (mainly motorbikes) that the Matoran use to cross the desert. In the desert, there is a temple that appears to be built by an ancient civilization.

The main residents of Po-Ostra are Po-Matoran, De-Matoran and Matoran of Plasma.


Ga-Ostra is the easternmost city on the Northern Island. The city has a shallow river that runs right through the


Two buildings in Ga-Ostra

middle. At the end, there is a hydroelectricity plant that powers the island (except for Le-Ostra). Most of Ga-Ostra's buildings have curved walls and roofs. This is because when it rains, the rainwater runs from the roofs, down the walls and into small gaps in the floor to be recycled. In the past 100 years, Ga-Ostra has had to build more and more houses to accommodate the Ko- and Ce-Matorans from Ko-Ostra after the collapse of the Ko-Ostran Mountains.

The main residents of Ga-Ostra are Ga-Matoran and Matoran of Electricity. Ko- and Ce-Matoran also live here because of the collapse of the Ko-Ostran Mountains.


Ko-Ostra used to be a thriving metropolis. Before the collapse of the Ko-Ostran Mountains, the city was used as a mining port for crystalized Protodermis, a substance that is generally used to forge jewelry and treasures.


Where the city of Ko-Ostra was

The Ko-Ostran Ruins, where the city was, is the only place that crystalized Protodermis is naturally formed, and is the only known reason Matoran go to the Ruins.

Ko-Matoran and Ce-Matoran used to live in Ko-Ostra before the collapse of the Ko-Ostran mountains.

Southern Island[]

The Southern Island is not a city, it is a large mountainous forest that only get sunlight for 5 hours a day. The Makuta use this island as

061104 moon1

Part of the Southern Island

their base of operations. Nozibak was stranded on the island when it separated from the Southern Continent and is now staying there by choice.

Only Makuta and Rahi live here.

Known Inhabitants[]

  • Matoran
  • Turaga
  • Toa
  • Makuta
  • Bone Bears
  • Vahki
  • Nozibak's Nuhkshi


  • Ostra Nui means "Great South" in the Matoran Language.
  • Nozibak once said that Ostra Nui his "first and only home" despite him actually being from Voya Nui.


  • The Hanrei Chronicles
  • All For One