Apocrypha is a realm of Oblivion created and ruled over by Hermaeus Mora, the Daedric Prince of Knowledge and Fate. The geography of the realm varies, with some areas being open with fields containing odd flora, other areas are an endless library consisting of untitled books with black covers, where all forbidden knowledge can be found, and the crackling towers of learning mingle with archways of despair and confusion. The realm is haunted by the ghosts of mortals forever searching for knowledge. Stacks of books form mazes and spiraling pillars that can reach as high as the illuminating green sky. Intricate ruins and monstrous carvings can be found among the stacks. The plane is covered in a sea of ink and roiling tentacles, while Hermaeus Mora is omnipresent over all, taking glee in tormenting mortals from his realm. Some areas of the realm are consumed by darkness which can kill any who enter it. Discarded pages and floating tomes fill the fetid air, as if pulled by invisible string. Storms of notorious strength purportedly rage over Apocrypha.

Description from the site - https://en.uesp.net/wiki/Lore:Apocrypha