Religious discussions here always go to the Judeo-Christian-Islamic Hell, but what of the Buddhist Hell? Any Atheists there?
The traditional concept is that the ego karma of one life generates another ego life after death (Reincarnation). That new life emerges in one of Six Realms:
The Animal Realm
The Human Realm
The Realm of Hungry Ghosts
The Realm of Fighting Demons
The Heavenly Realm
The Hell Realm.
If you build up the karmic legacy of impetuous behavior for short term survival, that karma is reborn as an animal.
If you're a fairly decent, fairly humane, sort of person, the next person will be Human.
Greed, Gluttony, Lust, and Addiction will have your successor life in realm of wretches struggling for scraps of satisfaction they can never obtain. They drift about as ghosts who can't get a hold on any tangible nourishment.
Competition, Envy, Self First, Power Grabbing, Dogmatic Imposition on others, all yield a realm of constant war where demigods battle on the wastelands just outside the borders of heaven.
If you've been an exemplary good person in spite of difficult life circumstances, the next life emerges in a wonderful place of the easy and good life.
The Human Realm is the best place to be to work toward Awakening, though some sects offer a Heaven-light called The Pure Land, where you can meditate without ordinary Human life interrupting. The other realms are just to full of painful distractions and obsessions to be a place one can reflect of reality. Even Heaven isn't optimal because it encourages complacency.
Contemporary Secular Buddhists take these "realms" metaphorically, as characterizing the karma of ones present life and its challenges to Enlightenment.
Got some Atheists in Hell? I'm afraid so, and some in Heaven as well.
One could suppose that some very militant Atheists are in the Realm of Fighting Demons. I don't think we have many Animals here. Though Cats of a sort, yes.
Oh, and there's one more fringe outcome: rebirth as a kitchen utensil, tool, or appliance.
Got any tools here?