Citadel of the Avesians

The Citadel of the Avesians is an ancient Matoran temple ruin located in central Vo-Powai on Powai Nui.

Early History
The current consensus among Powai Nuian scholars and historians is the Citadel of the Avesians was constructed by an extinct single-Element Matoran tribe of an unknown Element tribe known only as the "Avesians", from which it's current nickname is derived from. The Avesians were named for their fascination with bird Rahi ("Avesi" is the Archaic Matoran word for bird), especially the Kupurero. It is believed that the Grand Augur in the temple was used in conjunction with the clairvoyant birds in some sort of ritual in order to dictate future events. What these rituals constituted is unknown, but they may have involved the three other extinct bird species depicted on the temple's pillars. Some theorize that these species may have had other supernatural powers due to the fact that they are represented equally as much as the Kupurero.

The destruction of the Citadel marked the first time it was referenced in any surviving ancient text. A manuscript written by a member of a belligerent Ta-Matoran tribe describes it's attack on the Avesians, which apparently resulted in "nothing being left but buildings." It is unknown if this was merely a figure of speech or if the bodies of the Avesians were lost of destroyed, likely through cremation. Although this Ta-Matoran tribe was also wiped out later, the remains of it's people have been found, among which there were artifacts similar to those found near the Citadel.

Creating the Toa Powai
After reading a translated Kupurero recording which told her that Lewok, Detras, Corduk, Salvina, Navahko, and Wreshi were to become Toa, Toa of Lightning Maroona gathered them to the Citadel and told them of the prophecy. After allowing them to decide, they all agreed to become Toa, and they all placed their Toa stones on the Grand Augur and were transformed into Toa. Following this, the Powai Nui Governing Coalition placed heavy restrictions on who could visit the site in order to discourage future Toa transformations, fearing that they could result in a possible "Toa outbreak."

Description
The Citadel was circular, with a diameter of approximately 25 meters. It consisted of a thick retaining wall built from large stone bricks which extended a dozen meters into the ground, where there was a basin constructed of a similar material. There were four pillars spaced around the top of this wall which once supported a ceiling which has now collapsed. Each depicted one of the four environmentally divided regions of Powai Nui through birds native or formerly native to it. One of these pillars depicted the Kupurero, the other three's birds are believed to be extinct.

In the center of the basin was fifth, thicker pillar which rose up to the same height as the retaining wall. On it's top was another basin, this one filled to the brim with dark red igneous rocks. As there have never been any volcanoes on Powai Nui at any point in time, it is impossible for the rocks to have originated there; their origin is still being debated. It is also unknown how deep the basin of rocks extends.

Situated on the igneous rock in the exact center of the Citadel is the Grand Augur,a rotunda-shaped shrine composed of galvanized metal and mechanical components and coated with maroon paint, most of which has now peeled off. This device, while likely not intended for use as a Suva, can act as one, as evidenced by it's hand in transforming six Matoran into the Toa Powai.

Appearances

 * Against the Storm/Volume II (First Appearance)

Trivia

 * The word "Avesians" was derived from "Aves," the taxonomic name for birds. The Grand Augur was named after a religious official in ancient Rome who would use the behavior of birds to determine whether a proposed action was to be taken or not.
 * The walls of the Citadel's basin are used for scenes in the tunnels of the KCO.