The AI Containment Facility is a high security storage center for the Freelancer AI's. It contains every AI from the rejects, the bad variants, and even the Alpha (which had been moved from the Facility) and apparently Epsilon. In Chapter 15 of Reconstruction, Washington mentioned that other Freelancers aside from himself, have tried to infiltrate the Containment Facility, but failed in the process.
Layout
The facility seems to be fairly large. There is a main corridor, and off to the sides, are the libraries of storage which house the AI. The storage units seem to be three-demensional. The area is in the Halo 3 level Epitaph