Plunge Pool Cavern

Upon falling unconscious or dying, many characters have experienced seeing cavern with a plunge pool (not as glam as it sounds). Upon entering the pool, characters are pulled down towards the end, where they pass The Sphincter and are carried to The Waters/ The Stem.
The cavern has no obvious exits except for the pool, though Moonlight Through Rain once found a way back through a fissure that she forced into a doorway at the back of the cavern.
Since Qwyn blasted open The Sphincter the pool has no water, though whether that will remain the case over time is yet to be seen.
Occasionally characters see other visions in unconsciousness, but this is usually because they were battling Lycanthropy or getting Spiritually yeeted.
Alarë Awarthiel is the only known character to have not gone to the Cavern upon unconsciousness or death. Instead, she arrived at the Tiefling Afterlife(?).