Ghost Library

Timeless Library of the Deathless Revenants, or TLDR for short, this ancient ghost library is contained in a partially-ethereal living dungeon that rests on a formerly floating island.

To restart civilization in a past age, they opened a slightly more accessible branch in what was the Imperial Capitol. Things there went a bit sideways.

A scrivener once sent from the main branch: "...the ambered memories, stacked vessels in the flesh of trees. Autoluminescent and fogged. I am certain my answers shall be found here, although they may be that nothing more remains. This [uneaten?] messenger shall bear this note faithfully."