Pony General:"Season 12 will never air" edition.

Also a food for thought for episode 20:

 Spoiler

By technicality Hell is canon in the show, because that's what Tartarus is supposed to be, not to mention having an actual Cerberus as a gatekeeper. Makes you wonder what evils lie tucked away in Ponyville. Also worth nothing that this is probably why Discord was stoned and kept within Celestia's watch. Imagine what madness he can pull if he was free while in Hell. Mind rape ALL THE MONSTERS.

 Spoiler

Tartarus is not Hell (as per christian belief). It's just the place where everyone who died went, there was no distinction between the good or bad people.
And according to what they've said in the show it's just a place where monsters are kept guarded, so it could just be some kind of freaky zoo/prison.