The Archives (officially, the Archivae), as distinct from the Bene Gesserit Library and the Chronicles of the Chapter House, is a private collection of the Sisterhood's records, files, papers, and literary collections, so private that only a select group of Reverend Mothers has access to it. The Archivae is located on Wallach IX, under the main Chapter House building in three levels of subterranean vaults. In order to enter the Archivae, one must traverse a series of mazelike tunnels connected by shafts with lifts — obviously once powered by machinery but now traversed by one's own muscles. In order to facilitate the Dar-es-Balat research work, the Bene Gesserit has opened a portion of the Archivae to Ahna Judehic, linguistic historian, whose work is associated with that of R.M. Cassius Ida Treac. Supervising and directing the translation work is R.M. Marcellus Irulan Moiam. Only those sections of the Archivae containing documents pertaining to the history of the Atreides family and the more public aspects of the history of the Sisterhood have been made available for study.