Tartarus

tar'ta-rus, in Greek mythology, a sunless pit as far below Hades as earth is below Heaven. After Zeus had overthrown Cronus he imprisoned that god, together with the Titans, in Tartarus, closing the pit with gates of adamant. The later poets describe Tartarus as that part of the infernal regions where the shades of the wicked are punished. The word is used sometimes as synonymous with Hades. See Hades; Zeus; Cronus