Babd Catha Forerunner vessel

The Babd Catha Forerunner Complex was an ancient Forerunner complex on the planet Reach. It was located underneath Sword Base on the Babd Catha Ice Shelf. The structure was massive and appears to be roughly disk-shaped; as most of it was buried by a glacier, its true size is unknown. Parts of the structure were also visible from a nearby mountain range. The structure was positioned at a tilted angle, indicating it was not secured to the ground. As such, it may have once been levitating, or even a spacecraft, though the truth may never be known. The interior of the complex houses a holographic Forerunner data terminal of some kind.

History
It was the home to one of Dr. Catherine Halsey's labs, and had evidently been under excavation by the Office of Naval Intelligence for some time.

According to Dr. Catherine Halsey, the complex held secrets that could turn the tide of the Human-Covenant War — a "latchkey" discovery that Halsey compared to the invention of the conical bullet and the Shaw-Fujikawa Translight Engine. However, when the Covenant began attacking the facility on August 29, 2552, the decryption was only partially complete. Using Wolf Spider turrets, Noble Team was able to hold off the Covenant for long enough until Halsey could finish the decryption. The complex, along with Sword Base was completely destroyed by an explosive charge.

Exactly what data Halsey discovered within the complex was never revealed, but it may have been the location of or information about Halo.

Trivia

 * The Babd Catha complex marks the second large Forerunner complex on the planet Reach, perhaps suggesting that Reach was somehow important to the Forerunners.
 * In a commentary video for the multiplayer map Breakpoint, one of the map's designers presented the idea that the reason for the structure's tilted angle and unusual placement was a result of an accident with teleportation. However, they were quick to denounce the canonicity of the idea, leaving the actual reasons uncertain.

List of appearances

 * Halo: Reach