Level 37 — commonly called the Poolrooms in Backrooms lore — is an endless run of tiled swimming pools and shallow water stretching away under a sourceless, sunlight-like glow. In the current canon it carries the name "Sublimity." Only the sound of water and its reverberations fill the silence, and no exit is ever visible.
Its dread comes not from ugliness but from beauty. The dissonance of a place as calm and clean as a resort yet entirely empty of people produces deep unease without any violence at all. It is the defining crystallization of the liminal-space aesthetic into a quiet horror that is "more frightening because it is beautiful."
The Poolrooms arrived later than the Backrooms. Where the Backrooms began in 2019 from a single photograph and a few lines on an imageboard, the Poolrooms spread in 2022 through a series of renders by the 3D artist Jared Pike, who was working from a dream. The two spaces have different textures because of it — the Backrooms is yellowed wallpaper and fluorescent stuffiness; the Poolrooms is water-light and clean tile.
That cleanliness is what touches memory. The essential feeling is of a place you seem to have been — a childhood swimming pool, a hotel basement, a water park after closing — that refuses to resolve into any particular one. The structure makes you nostalgic for a memory you do not have, so fear and nostalgia issue from the same place.
Having several canons at once is also part of its character. Level numbers and names differ from wiki to wiki, settings diverge, and the question of which version is real has no answer. It is less a place than a pile of versions of a place.