Panopticon

The Panopticon was the main room of the Capitol on Gallifrey. It served as the Time Lords' parliament and seat of State. (PROSE: Engines of War) The Eye of Harmony was secretly kept under the Panopticon. (TV: The Deadly Assassin)

Structure
The Panopticon had six sides, one for each of the Founders of Gallifrey. At every corner of the Panopticon, there were six black statues of the six founders of Time Lord society (Rassilon, Omega, Pandak, the Other, Apeiron and one other, possibly Eutenoyar). Every college (Prydonian Chapter, Arcalian Chapter, Patrex Chapter, Dromeian Chapter, Cerulean Chapter and the Scendeles Chapter) was involved in a competition to build a bigger statue of their founder than the other Chapterhouses, which resulted in the Scendeles Chapter being bankrupted. (PROSE: The Ancestor Cell) When Gallifrey's suns shone on the Panopticon, the interior glowed turquoise. (PROSE: The Tomorrow Windows) The Panopticon's ceiling was so high that clouds formed near it, and sometimes it rained. (PROSE: The Eight Doctors, Warmonger)

Pre-Time War
In ancient times, the Pythia used panoptics placed throughout the city to watch over it. (PROSE: Cat's Cradle: Time's Crucible)

As a child, the First Doctor played in the tunnels under the Panopticon. (AUDIO: Order of the Daleks)

Time War
The Panopticon was badly damaged by a Dreadshade unleashed by the Twelve, however the General told the Eighth Doctor shortly afterwards that work was starting on rebuilding it. (AUDIO: Dreadshade)

As acknowledged in the Dalek Combat Training Manual, 700 Wonders of the Universe by Co-ordinator Engin and Orcini and the Battle of Vavetron by Commander Andred were avaliable in the Panopticon Library. (PROSE: Dalek Combat Training Manual)

In the last days of the Last Great Time War, the War Doctor, after discovering the Dalek Temporal Cannon, dramatically materialised in the centre of the Panopticon as a way of quickly getting attention. (PROSE: Engines of War)

Post-Time War
When allied himself with the Cybermen, he redecorated the Panopticon with statues of his prior incarnations. He later took the Twelfth Doctor and the Twelfth General there to access a hidden lift that led to the Eye of Harmony. (COMIC: Supremacy of the Cybermen)

When a temporal crisis made TARDIS-travel difficult throughout time and space, the Panopticon was one of the Waypoints soaked with vortex energy between which travel was still possible. It was there that the Twelfth Doctor's TARDIS was initially drawn; the Doctor found a cache of Kyfred Gems and explained to Bill Potts, as they stood in the Panopticon, that he hoped to toss them through the Untempered Schism like "skipping stones" to stabilise the temporal energies. Later, K9 Mark IV, using his vortex manipulator circuit, gathered Sarah Jane Smith and Rose Tyler in the Panopticon. They wore perception filters to avoid being noticed, but, all the same, decided to head off to somewhere more private to continue their conversation. Meanwhile, Bill returned to the Panopticon where she was met with Nardole, who had thus far stayed in the TARDIS, so discreet that Bill hadn't previously realised Nardole had tagged along on this particular TARDIS trip. (GAME: Lost in Time)

After taking the Thirteenth Doctor to the ruins of Gallifrey, pointed out the door leading to the remains of the Panopticon, reminiscing about the times he and the Doctor had had inside of it. (TV: The Timeless Children)

Other realities
In one of the infinite parallel universes of "possible space", (COMIC: Fire and Brimstone) the Panopticon existed in the Domed City of Gallifrey. It contained the Matrix. The tradition of an outgoing President gathering other Time Lords there to announce their successor existed there (PROSE: The Chronicles of Doctor Who?) as it did in the Fourth Doctor's reality. (TV: The Deadly Assassin)

Behind the scenes
The name (derived from Greek: "pan" meaning "all" and "Opticon" meaning "view") was coined by Jeremy Bentham for a revolutionary approach to the way prisons should be designed.

Panopticon