Phlegethon

Not to be confused with the black/funeral doom metal band Flegethon from St. Petersburg (early); Baikonur, Kazakhstan (later).

In Greek mythology, the river Phlegethon (Φλεγέθων, "flaming") was one of the five rivers in the infernal regions of the underworld, along with the rivers Styx, Lethe, Cocytus, and Acheron.