In Greek mythology, the souls of the dead went to Hades, the underworld, where they led a grim, soulless existence. Those singled out for harsh punishment were sent to an area beneath Hades: Tartarus, en eternally dark land full of horrors, such as many of the original Titans thrown down by Zeus and the other Olympian Gods.
According to ancient legends, there are five rivers which cross Tartarus and/or Hades (the nature of the ancient histories makes specific geography of either ancient mythological region impossible). All five of the rivers are associated with some sort of human emotion.
Acheron, River of Pain or Woe: a wide, swampy river, the Acheron is the first river that Dante and Virgil must cross in Dante’s Inferno, and it divides the truly suffering souls from the neutral ones. Charon the boatman ferries the souls of the dead (those that can pay him, anyway) across the Acheron (in some ancient myths, he ferries them across the Styx).
Styx, River of Hatred: the mighty River Styx was important to the Gods: Zeus made mortals swear by its waters. Styx was a goddess who supported the Olympians against the Titans and was made into a river. Although the Styx was the river of hatred, its waters could confer a blessing: Thetis, the mother of Achilles, dipped her infant son in the River Styx, making him invulnerable except for a spot on his heel where her thumb held him. In some later versions of Greek myths, Charon the boatman carries souls across the Sytx instead of the Acheron. In Dante’s Inferno, the muddy banks of the Styx are home to the wrathful and sullen.
Phlegethon, River of Rage: The Phlegethon is a mighty river of fire: in some myths it encircles Tartarus, forming a barrier. In Dante’s inferno, those guilty of violent crimes against others spent eternity in the river, which ran with hot blood. In most myths, the Phlegethon could burn but never consumed what it burned.
Cocytus, the River of Lamentation: the Cocytus was the home of those souls who were not properly buried and must spend one hundred years wailing. In Dante, the Cocytus is a lake frozen by the constant flapping of Lucifer’s wings as he tries to escape.
Lethe, the River of Forgetfulness: a drink of its waters would cause anyone to forget everything they knew. In the Iliad, Aeneas’ father shows Aeneas the souls waiting for a drink from the river: they must drink and forget before being reincarnated. In Dante, the Lethe only removes negative memories.
These five rivers often play minor roles in other legends: Achilles being dipped in the Styx is one such example. In another myth, the bard Orpheus must cross the Styx in order to bring his beloved wife back from the dead.
