A vast, centuries-old archive of the galaxy's knowledge, hidden in the plasma storms of the Badlands in 3191, where Burnham finds the last clue to the Progenitors' technology in the episode Labyrinths.
The Eternity Gallery and Archive is a space station seen in the fifth-season Star Trek: Discovery episode Labyrinths. It is an independent library that has gathered books and artefacts from countless cultures over the ages and moves from place to place to keep them safe. In 3191 it lies inside the Badlands.
Discovery is welcomed by the cheerful Efrosian archivist Hy'Rell. The final clue left by the 24th-century scientists is hidden in a Betazoid manuscript called Labyrinths of the Mind, and when Burnham touches it she is drawn into a test inside her own mind, which she passes only by admitting her fear of failure.
Meanwhile the Breen arrive and bombard the Archive to get the clue, and Burnham gives it up to save the station. During the visit Book is given a cutting of the World Root of his lost planet Kwejian, which the Archive had preserved.