Lua
The Orokin lunar centre, hiding place of the Tenno Reservoir, and the lost world Lotus carried into the Void.
MOON · RESERVOIRFULL SPOILERS
The Reservoir
This is where the Operators' bodies sleep in Somatic Pods. While the Warframes fight, the real Tenno are kept here; the Stalker and Hunhow mean to end every Tenno by destroying this one place.
Orokin records
Lua's halls carry records of the war, of Margulis and of the principles of the Seven. The Moon's return is as much the return of a suppressed history as of a physical place.
Its role today
It is a target for Sentient, Grineer and Corpus forces; Spy vaults and sealed halls preserve the old technology. The transition in The Lotus Eaters also turns Lua into the start of a new path through time.