The living museum of ONU-METRU, which extended far below the surface and below many other metru as well. Here could be found virtually every tool, artifact, and creature of METRU NUI’s past. Staffed by a large number of ONU-MATORAN, it was once the workplace of WHENUA before his transformation into a TOA METRU.
RAHI kept in the Archives were held in stasis for safety purposes. Each Rahi was placed inside an inner stasis tube which was surrounded by a clear casing. While in the stasis tube, their life processes were slowed to an extreme degree. They were alive, but not aware, and could remain in that state for thousands of years. Damage to the outer case would not affect the Rahi, but damage to the inner case would cause it to awaken.
The Archives were known to contain levels, sublevels, and maintenance tunnels. Some sublevels featured creatures considered too dangerous to exhibit publicly. The museum could be accessed through a number of entrances, all of which were guarded. The locking mechanisms was a series of hidden switches that had to be hit in a certain order.
Creatures known to have been in the Archives included RAHKSHI, the TWO-HEADED TARAKAVA, the USSAL hybrid, a NUI-RAMA, a MUAKA, and the ARCHIVES BEAST. KRAHKA and other creatures lived in the maintenance tunnels beneath the Archives.
The Rahaga used the Archives as a base for years prior to the coming of the VISORAK and his the AVOHKII there. A massive earthquake later shattered the Archives, releasing all of its exhibits into the city.
Source: BIONICLE Encyclopedia Updated