/lit/ - Literature

Could anyone recommend a fantasy/scifi book where the story takes place in, or is centered around, some concept that isn't entirely clear, and may be surreal or metaphoric in some sense?

For example, the maze in the Maze Runner, where it is presented as a ominous, fantastic creation that initially defies logic. Or the Shrike in Hyperion, a creature so powerful and obtuse, that no one really knows what it is, as it defies time and space. Or At the Mountains of Madness, where the things the author reads about are ancient, terrifying civilizations and creatures that defy human logic.

Just looking for something fantastic and mysterious to get me interested in the outcome.