Phlegethon

In Greek mythology, the river Phlegethon (Φλεγέθων, English translation: "flaming") or Pyriphlegethon (Πυριφλεγέθων, English translation: "fire-flaming") was one of the five rivers in the infernal regions of the underworld, along with the rivers Styx, Lethe, Cocytus, and Acheron.
According to Homer's Odyssey, the Phlegethon feeds into the river Acheron, alongside the Cocytus. Plato describes it as "a stream of fire, which coils round the earth and flows into the depths of Tartarus".
In Orphic literature, in which there are... meer