Falkus

Falkus was an artificial moon of Skaro. Falkus orbited Skaro three times every twenty-four Earth hours. In the Kaled language, its name meant "new dawn". By one account, it was the second moon of Skaro, (AUDIO: Daleks Among Us) though by another, it was the planet's first moon. (AUDIO: Restoration of the Daleks)

History
During Davros' youth, both it and Omega Mysterium could be seen clearly from his father Nasgard's house on Drammankin Lake. Elsewhere on Skaro, they were obscured by the high levels of radiation in the atmosphere. (AUDIO: Innocence)

The Doctor once battled the Klade on Falkus, accompanied by "a tall man and a dark skinned woman." The Eighth Doctor did not remember the event, either implying it had been erased with his memories or had yet to happen. (PROSE: Father Time)

During the Last Great Time War, a version of Davros was imprisoned on Falkus following his resurrection by the Dalek Time Strategist. (AUDIO: Restoration of the Daleks) Davros was kept in a recreation of the Thousand Year War with Kaled clones, however managed to gain control of the prison’s computer which enabled him to send a message to Gallifrey, offering to aid the Time Lords in return for rescue. The Doctor, in the midst of a degeneration causing him to appear as the Seventh Doctor, and Commander Veklin travelled to Falkus and retrieved Davros, however they were pursued by Daleks who recaptured them, along with the General, and brought them back to Falkus. On his return Davros used his control of the facility to turn the clones on the Daleks, trapping them all on the moon until the Doctor exposed the giant Dalek mutant at the heart of the facility to his unstable genetics. This resulted in an explosion of artron energy which destroyed Falkus entirely. (AUDIO: A Genius for War)

Origins
Falkus was created by the Daleks based upon Davros' plans. The city under its surface was a living machine. It could repair and service itself, hear, see and feel. The Daleks also built Falkus with defensive capabilities should it ever be attacked.

The Daleks who built Falkus had their memories wiped so they did not know its true purpose. (REF: Doctor Who and the Daleks Omnibus)

Purpose
Falkus served as a sanctuary for the Dalek race and all Daleks would think of Falkus with a sacred quality although none of them knew of its true function. Only the Dalek Supreme knew Falkus' purpose: a planet-sized Dalek gene-bank capable of creating thousands of Daleks in mere seconds.

Falkus was created as the Daleks' last hope in the face of extinction. The living mind of Davros resided within the heart of Falkus, ready to be placed in a new body and start the production in the factory should the Daleks ever become extinct. The Dalek Supreme would visit Falkus every hundred years in a one-man shuttle to make sure Falkus was still running. (REF: Doctor Who and the Daleks Omnibus)