Hell. The place where the earths true scum end up... I guess people say that about hell... but truthfully, it's very different. Essentially... hell is where most people end up. This is because you kinda have to be... let's say perfect if you even want a chance to get into heaven. It's not like hell is good or anything... no, not at all. Human's who arrive in hell are usually tortured for years upwards in order to repent for their sins... and even after that they're sold as slaves anyway...

But, if you're a demon, or lucky enough not to get sold on (and can deal with the temperatures) hell isn't too bad. Hell is made up of 7 kingdoms, each ruled by a demon lord/lady... each controlling one of the "fragments" of hell, several areas of land that surround the central city, which obviously, Lucifer resides in. These demons, along with Lucifer, rule hell.

With large sprawling city's that span miles on end to teeny tiny villages lost in the burning mountains, hell is less of, "eternal suffering" and more of "casual society with demonic tweaks".

Now the real question is, how is your story gonna go down in the underworld?