The afterlife. A place where people go after they die. That's what this is. Various works and religions and other things portray the afterlife as various different places. Among other things, we have Tartarus and Elysia from Greek mythology, and the Underwhere and Overthere from Super Paper Mario (and, possibly, the entire Marioverse.) This possible trope covers such instances of Afterlife appearances where the locations are not named Heaven and Hell. Needs a Better Title
Hello, Unknown Troper. You'll need to get known to lend a hand here.