Central AI Chamber

The Central AI Chamber is a large bay housing the central core machine, which GLaDOS is in place of. This chamber serves as the setting for many major events in Portal and the single-player campaign of Portal 2.

Throughout the series, GLaDOS controls many aspects of the Aperture Science computer-aided Enrichment Center with her position as the facility's central core. The chamber is destroyed after the events of Portal.

Portal
The room was a large octagonal chamber set in the center of the Enrichment Center. At the climax of Portal, after Chell had escaped from the testing tracks, she had made her way through the entire facility in hopes of escape, instead she is led to the Central AI Chamber where she is to confront GLaDOS.

It would appear that GLaDOS did not intend to bring Chell to her chamber, but to take advantage, she allows Chell to destroy her Morality Core - which in turn breaks the restriction of her need to kill anyone directly. GLaDOS then begins pumping neurotoxin, and deploys a Rocket Turret. Eventually Chell manages to destroy all of GLaDOS' personality core attachments, which destroys GLaDOS in the process. When Chell is awakened outside in the parking lot after awakening from the destruction of the facility, it is indicated that the chamber is considerably close to the surface.

Despite that most of GLaDOS' components were scattered around the parking lot, she seems to have been scattered around in the chamber again during the beginning of the single-player campaign in Portal 2. This may have likely been the work of the Party Escort Bot that dragged Chell back into the facility for extended relaxation.

Portal 2
Since Portal 2 is set thousands of years after the events of Portal, the entire Enrichment Center has been degrading and overgrown. And most personality cores that were awakened after the destruction of GLaDOS has long since been corrupted or destroyed in the surroundings. In turn, no personality cores have tried to reactivate GLaDOS or to replace her position as the central core with themselves since the chamber is out of their reach. The Central AI Chamber is evidently untouched for centuries.

When Chell and Wheatley journey across the Central AI Chamber during the beginning of the single-player campaign, they are forced to enter the main breaker room beneath the chamber in an attempt to access an elevator to the surface. As they enter the breaker room, Wheatley accidentally triggers all the wrong buttons and ends up lifting each other back to the main chamber and reactivating GLaDOS in the process.