The River Styx is a significant feature in ancient Greek mythology, often depicted as a boundary between the Earth and the Underworld. It is said to be a river that souls must cross to reach the realm of the dead, ruled by the god Hades. The river is associated with themes of death and the afterlife, and it is often described as dark and murky. In mythology, the ferryman Charon transports souls across the Styx, but only if they have received proper burial rites. Those who could not pay him were said to wander the shores for eternity. The Styx symbolizes the transition from life to death and the importance of honoring the deceased.