Zero Room

Zero Room
An important room in and part of the TARDIS

Overview
The Zero Room was an atmospheric and calming room that are important to all, Timelords included. This became true for the fifth Incarnation of The Doctor. When The Doctor's regeneration failed, The Doctor used the Zero Room (DW: Castrovalva) to help him become better.

End
The end came for the Zero Room when the TARDIS needed to eject part of its structure in order to boost itself out of danger. However, it lived on from becoming a smaller capsule built by Nyssa