Tartarus

Tartarus, according to Homer, is a deep and sunless abyss, as far below Hades as earth is below heaven, and closed in by iron gates. Into Tartarus Zeus hurled those who rebelled against his authority, as Kronos and the Titans. Afterwards the name was employed sometimes as synonymous with Hades or the under-world generally, but more frequently for the place of damnation where the wicked were punished after death. See HELL.