Though the Guardians of the Universe were virtually immortal, their agents, the three thousand six hundred members of the Green Lantern Corps, were not. In the three billion year history of the Corps, literally millions of Green Lanterns gave their lives in the line of duty.
The Oans sought to honor their champions by following their ancient Maltusian burial customs. The Green Lanterns were entombed in one vast crypt. Each Green Lantern was placed in a crystalline sarcophagus, apparently preserved for all time.
The Crypts of the Green Lantern Corps was buried deep beneath the main Citadel and extended outward under the Oan sands. As part of the Maltusian customs, the heroes were close to the quarters of the living so the souls of the living and the dead could commune.
Many honored Green Lanterns were placed here, including Tomar-Re of Xudar, Abin Sur of Ungara, Arkkis Chummuck of Toomey IV, and Ahtier of Glazzonio. In Abin Sur's case, it appears his body was retrieved from Earth, where he had been buried by Hal Jordan.
[Guy Gardner Reborn #3, Green Lantern Vol. 3 #0, Showcase #22]
Even Sinestro was entombed in the Crypts. He was executed by the Green Lantern Corps and his spirit inhabited the Central Power Battery. His sarcophagus was by itself, separated from the rest of the Corps.
[Green Lantern Corps #222-224, Guy Gardner Reborn #3]
After leaving the Green Lantern Corps, Guy Gardner returned to Oa to retrieve Sinestro's yellow power ring. Gardner found the sarcophagus unbreakable.
John Stewart went to stop Gardner, but he was taken over by the spirit of Sinestro. After his spirit left the Central Power Battery, the Korugarian had spent months trying to find his body. Gardner's actions led him straight to it.
Though Sinestro had the experience, intelligence, and control, he could not take the ring. Guy Gardner beat the evil spirit in a battle of wills to claim the ring.
[Guy Gardner Reborn #3]
In the ensuing months, other Green Lanterns fell. Pathavim Seth-Ottarak may have joined the honored dead in the Crypts of the Green Lantern Corps.
[Green Lantern Corps Quarterly #1]
After his failed attempt to remake the universe, Hal Jordan, now known as Parallax, returned to Oa. He could replenish himself on the homeworld of the Green Lantern Corps.
Jordan convinced his successor, Kyle Rayner, to give him the power ring. He felt threatened by Rayner, so Jordan blasted a crater into the Oan sands.
Rayner fell through the hole into the crypts. Jordan followed him, but was unprepared for the changes in the ring. The sarcophagus of Abin Sur was overturned on him, but Jordan had counted on the ring's safety feature to protect him. Rayner took back the ring.
Jordan absorbed enough power to fight the young ring wielder. The two battled amongst the dead until Rayner destroyed Oa to take away Jordan's power.
[Green Lantern Vol. 3 #0]
Script: Gerard Jones
|CREATIVE TEAM (First Appearance)|
Pencils: Joe Staton
Inks: Josef Rubinstein & Jose Marzan Jr.
Colors: Digital Chameleon
Letters: Albert DeGuzman
Edits: Kevin Dooley
Many Green Lanterns were larger than humanoids, and the crypts were presumably three billion years old. With the sheer number of fallen, the crypts would have easily been filled, long ago. The area the vast tomb comprised would have been more than Oa could support. I think the crypts were actually a tesseract. The outside of the Crypts could be of finite dimension, with unlimited storage space inside.