Originally posted on DC Comics website before the Green Lantern movie. Not the original pics that were posted.
REAL NAME: Oa
OCCUPATION: Headquarters for Green Lantern Corps
BASE OF OPERATIONS: Sector 0
FIRST APPEARANCE: Green Lantern vol. 2 #1 (July/August, 1960)
AKA: Center of the Universe
BACKGROUND from the comic books:
The barren, lifeless world of Oa is one of the oldest planets in existence. The immortal Guardians of the Universe migrated from Maltus to Oa to facilitate in bringing order to the universe. Its location at the center of the cosmos made it an ideal choice for the headquarters of the Green Lantern Corps.
The sacred Book of Oa is located in the Hall of Great Service and is considered the law book of the Green Lantern Corps. It catalogues the history of the universe as well as prophesies of the future. Due to the amount of classified information inside, many sections are only accessible by the Guardians.
The Guardians of the Universe can be found within the Planetary Citadel. From this location, they track events occurring throughout the galaxy and dispatch a Lantern wherever necessary. Positioned north of the Citadel lies the Hazard Simulation Facility where Lanterns brush up on new tactics and train with drill sergeant Kilowog. The city is also home to The Crypts, a memorial honoring all fallen Lanterns that is overseen by Green Lantern Morro. Heavily guarded beneath Oa are the Sciencells, the highest secured prison facility in the galaxy, run by warden Lantern Voz.
Center of the universe.
Base of operations for the Guardians of the Universe and the Green Lantern Corps.