What role does the Styx River serve in mythology?

The Styx River plays a significant role in mythology, particularly in Greek mythology, as a boundary between the world of the living and the underworld. It is depicted as a river that souls must cross to reach the realm of Hades, the god of the underworld. The crossing of the Styx is essential, as Charon, the ferryman, transports the souls of the deceased across it, highlighting its function as a barrier that separates life from death. The River Styx is often associated with oaths and promises, with the idea that swearing an oath upon it invokes a sense of gravity and solemnity due to its connection to the afterlife. This illustrates its central role in the mythology regarding death and the journey of souls, affirming that it acts as a significant barrier to the underworld. The other options describe concepts that do not align with the established representations of the Styx in mythology.