Mythology & Beliefs: Cocytus In Greek and Roman Mythology, Cocytus was one of several Rivers of Underworld.
Cocytus in Wikipedia
Cocytus or Kokytos, meaning "the river of wailing" (from the
Greek κωκυτός, "lamentation"), is a river in the underworld in
Greek mythology. Cocytus flows into the river Acheron, across
which dwells the underworld, the mythological abode of the
dead. There are five rivers encircling Hades. The River Styx
is perhaps the most famous; the other rivers are Phlegethon,
Lethe, and Acheron...