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Percy Jackson describing the river, Percy Jackson's Greek Gods

The River Cocytus, sometimes spelled River Kokytos, is a river found in the Underworld. It is also known as "The River of Lamentation" or "The River of Wailing."


Cocytus flows into the River Acheron, across which is the underworld, the mythological abode of the dead. It is said to wind peacefully through Erebos' plains.


The River Cocytus was described as a dark blue river, flowing in a vast cavern deep in Tartarus. The river was a ribbon of glittering, dark liquid with a smell of sulfur. It also appears to have a mind of its own, trying to attack Percy Jackson and Annabeth Chase with feelings of grief. Cocytus' water is freezing cold, filled with millions of heartbroken voices, as if the river were made of distilled sadness. If dipped in, the person's thoughts will become sad and miserable, having no purpose to live.

The Heroes of Olympus

The House of Hades

Annabeth and Percy finally fall into the river after falling for a long period of time. Percy tries to create a whirlpool to get them out, but falls under the river's spell, causing him to become miserable with hopelessness. Annabeth tells Percy to start talking about New Rome and their life together there, while Annabeth drags Percy and her to shore. Eventually, they reach the shore and escape the freezing water.


Underworld: DOA Recording Studios | Doors of Death | Door of Orpheus | Elysium | Erebos | Fields of Asphodel | Fields of Punishment | Hades' Palace | Isles of the Blest | Judgment Pavilion | Persephone's Garden
Rivers: Cocytus | Phlegethon | Styx | Lethe | Acheron
Tartarus: Mansion of Night | Hermes' Shrine | Chaos