In the book in the shadow trilogy Hell's Asshole was the name for the pit they put the worst of the worst in. There was a hole in the botttom that sounded like it shrieked and wailed it also smelled of sulphur. Hence Hell's asshole.
Civi 1: Did you here about that pedo?
Civi 2: The one that got sent to Hell's asshole?
Civi 1: Yeah, that's the one.