In Dante’s Inferno, the river Styx forms the marsh where the wrathful are punished. Dante and Virgil reach the marsh in the fifth circle of Hell, where the angry souls attack one another on the surface while the sullen lie submerged beneath the muddy water.
The Styx comes from classical Greek mythology, where it is one of the rivers of the underworld and is associated with oaths, death, and divine power. Dante adapts that tradition but gives the river a distinctly moral landscape: the wrathful are trapped in the same anger that dominated their earthly lives.
A common mix-up is Phlegethon, the river of boiling blood in the seventh circle, and Cocytus, the frozen lake of the ninth circle. Acheron is another underworld river, crossed near the entrance to Hell by Charon. In Dante’s version, the Styx is crossed by the ferryman Phlegyas, who carries Dante and Virgil toward the city of Dis.