The nether world (according to classical mythology, the abode of the shades, ruled over by Hades or Pluto); the invisible world; the grave.
Abode of dead, or king of underworld, of Greek myth; Hell.
In Greek mythology, the underworld where spirits went after death, usually depicted as a cavern or pit underneath the Earth, the entrance of which was guarded by the three-headed dog Cerberus. It was presided over by the god Pluto or Hades (Roman Dis). Pluto was the brother of Zeus and married Persephone, daughter of Demeter and Zeus.
Tartarus was the section where the wicked were punished.