Promethea is a planet whereupon the Atlas corporation found alien technology and subsequently reverse-engineered it in order to manufacture improved starships and weaponry with its benefits. The Crimson Lance also have a military presence on the planet, with which Roland served "two tours," as stated by General Knoxx.
Living conditions are presumably harsh, or at least worse than the already difficult life for Pandoran settlers, as an Atlas propaganda message at T-Bone Junction (when referring to the positive side of Pandora) states "...at least you're not on Promethea!". Citizens of Sanctuary occasionally comment to the same effect.
Promethea is largely a metropolitan world, having many futuristic buildings. In Borderlands 3, Promethea serves as the Atlas corporation's headquarters. It is sieged by Maliwan, turning the metropolitan wonderlands into a warzone. The Children of the Vault have taken this opportunity to recruit displaced and disgruntled citizens.
- In Greek mythology, Prometheus is the Titan who stole fire from Zeus to give to the human race. After the war with the Olympians, Prometheus defected to the side of the mortals. Pandora's Box was then created through Zeus' will as a sort of revenge on men for Prometheus giving them fire. Fire can be symbolically seen as the advanced technology the Atlas corporation acquired, with Pandora clearly being the planet on which Borderlands takes place.
- Promethea is Roland's homeworld.
- In Borderlands 2 the Hyperion sniper rifle Morningstar states that: "there are children on Promethea who can't afford ammo, you know!"
- In PAX East 2016 Gearbox Software teased that DLC missions for Battleborn would have easter eggs about next Borderlands game:
- In first DLC, graffiti was found with the word "Promethea" depicted; the Vault symbol instead of last letter "A" being present.
- All five stories contained hidden messages in audio signals which were decoded as:
"Visit Promethea / Children of the Vault / We are not on Pandora anymore / Tannis is not what she seems / Do not open the Vaults".