In classic Greek mythology, below Heaven, Earth, and Pontus is Tartarus, or Tartaros (Greek 'deep place'). It is either a deep, gloomy place, a pit or abyss used as a dungeon of torment and suffering that resides within Hades or the entire underworld with Hades being the hellish component In the Gorgias, Plato (c. 400 BC) wrote that souls were judged after death and those who received punishment were sent to Tartarus. As a place of punishment, it can be considered a hell. The classic Hades, on the other hand, is more similar to Old Testament sheol. Like other primal entities (such as the earth and time), Tartarus is also a primordial force or deity.
In Greek mythology, Tartarus is both a deity and a place in the underworld even lower than Hades. In ancient orphic sources and in the mystery schools Tartaros is also the unbounded first-existing "thing" from which the Light and the cosmos is born.
In Hesiod's Theogony, c. 700 BC, the deity Tartarus was the third force to manifest in the yawning void of Chaos. As for the place, the Greek poet Hesiod asserts that a bronze anvil falling from heaven would fall 9 days before it reached the Earth. The anvil would take nine more days to fall from Earth to Tartarus, making it approximately 4733.22 miles deep.
In The Iliad (c. 700), Zeus asserts that Tartarus is "as far beneath Hades as heaven is high above the earth." As a place so far from the sun and so deep in the earth, Tartarus is hemmed in by three layers of night, which surround a bronze wall which in turn encompasses Tartarus. It is a dank and wretched pit engulfed in murky gloom. It is one of the primordial objects which sprung from Chaos, the Abyss. Along with Tartarus, Gaia (Earth), and Eros, emerged into the universe.
While, according to Greek mythology, Hades is the place of the dead, Tartarus also has a number of inhabitants. When Cronus, the ruling Titan, came to power he imprisoned the Cyclopes in Tartarus. Some myths also say he imprisoned the three Hecatoncheires (monsters with fifty heads and one hundred arms). Zeus released them to aid in his conflict with the Titan giants. The gods of |Olympus eventually defeated the Titans. Many, but not all of the Titans, were cast into Tartarus. Cronus, Epimetheus, Metis, Menoetius, and Prometheus are some Titans who were not banished to Tartarus. In Tartarus, prisoners were guarded by giants, each with 50 enormous heads and 100 strong arms, who were called Hecatonchires. Later, when Zeus overcame the monster Typhon, the offspring of Tartarus and Gaia, he threw it, too, into the same pit.
Originally, Tartarus was used only to confine dangers to the gods of Olympus. In later mythologies, Tartarus became the place where the punishment fits the crime. For example Sisyphus, who was punished for telling the father of Aegina, a young woman kidnapped by Zeus for one of his sexual gratifications, where she was and who had initially taken her. Zeus considered this an ultimate betrayal and saw to it that Sisyphus was forced to roll a large boulder up a mountainside, but when he reached the crest, it rolled back down, again and again.
Also found there was Ixion, one of the mortals invited to dine with the gods. Ixion began to lust after Zeus' wife, Hera, and began to caress her under the table, but soon ceased at Zeus' warning. Later that night, having given Ixion a place to sleep, Zeus felt the need to test the guets's tolerance and willpower. Constructing a cloud-woman to mirror Hera in appearance, Zeus sent her, known as Nephele, to Ixion's bed. He promptly slept with and impregnanted the false Hera. As his punishment, he was banished to Tartarus to forever roll strapped to a wheel of flames, which represented his burning lust.
Tantalus who was also graciously invited to dine with the gods, felt he should repay them for their kindness and hospitality, but in his pride, decided to see if he could deceive the gods. Tantalus murdered and roasted his son Pelops as a feast for the gods. Demeter, one of the goddesses who preferred to walk with the mortals, graciously accepted the food, but was immediately repulsed when she bit into the left shoulder. The gods all became violently ill and immediately left for Mt. Olympus. As his punishment for such a heinous act, Tantalus was chained to a rock in the middle of a river in Tartarus with a berry bush hanging just out of reach above his head. Cursed with unquenchable thirst and unending hunger, Tantalus constantly tried to reach the water or food, but each time, the water and berries would recede out of his reach for eternity.
According to Plato (c. 400), Rhadamanthus, Aeacus and Minos were the judges of the dead and chose who went to Tartarus. Rhadamanthus judged Asian souls; Aeacus judged European souls and Minos was the deciding vote and judge of the Greek.
Plato also proposes the concept that sinners were cast under the ground to be punished in accordance with their sins the Myth of Er.