The Camper Festival is an odd phenomenon in OH GOD THE RAPTURE IS BURNING located in Xanadu.
It is an eldritch concert held for the duration of the five months of the apocalypse wherein rock acts are forced to play their most progressive works. The crowd seems to be entirely Camper, though Salmacis claims to have no idea what the festival's purpose is. The festival comes up a lot in the story, and it has been confirmed to have a significant purpose in the grand scheme of things.