Infinity Chamber

Infinity Chambers, also known as Cosmos, (PROSE: The Chronicles of Doctor Who?) were a technology which encapsulated the entire universe so that any part of it could be viewed. The Chambers drew their information from the Matrix's computer model of the universe which was accurate to the level of quarks, (PROSE: The Infinity Doctors) projecting it as a life-sized realistic hologram which a viewer could walk through. (PROSE: Just War, The Infinity Doctors)

This technology was prevalent on the Infinity Doctor's Gallifrey. (PROSE: The Infinity Doctors)

The Seventh Doctor once used an Infinity Chamber inside his TARDIS to relive a moment from his travels with Melanie Bush. (PROSE: Just War)

The Eighth Doctor's console room had a ceiling which showed the cosmos very realistically (TV: Doctor Who) in a manner using holograms. (PROSE: War of the Daleks) Similarly, in Barusa's universe, the Eighth Doctor had a similar console room with a wooden railing that overlooked the Galaxy through a "vast and invisible lens." (PROSE: The Chronicles of Doctor Who?)

Behind the scenes
The concept and name of "Infinity Chamber" originate from the Leekley Bible, where the Doctor's Cosmos balcony has the alternate name of "Infiniti Chamber". The general fandom were introduced to the term "Infinity Chamber" in an interview with Philip Segal in DWM 226 which was accompanied by artist Phil Bevan drawing a cinematic console room based off of the same descriptions which informed the Leekley Bible.