Styx

Styx, a river of Greek and Roman mythology, situated in the infernal regions, across which the dead were ferried by Charon, and by which the gods swore an inviolable oath. It was said to go nine times round hell, and Milton speaks of it as the "flood of burning hate." The real Styx is a rivulet in Arcadia, whose waters are said to be pernicious, and its modern Greek name embodies this idea.