The river of which many know its name, without knowing its origin or what it really stood for. A river that separates the world of the living from the world of the dead. Styx it is said winds around Hades (hell or the underworld are other names) nine times. Its name comes from the Greek word
stugein which means hate, Styx, the river of hate. This river was so respected by the gods of Greek mythology that they would take life binding oaths just by mentioning its name, as referenced in the story of Bacchus-Ariadne, where Jove "confirms it with the irrevocable oath, attesting the river Styx."
There are five rivers that separate Hades from the world of the living, they are:
- Acheron - the river of woe;
- Cocytus - the river of lamentation;
- Phlegethon - the river of fire;
- Lethe - the river of forgetfulness;
- Styx - the river of hate.
It is thought that Charon, the old ferry man who ferries the dead onto the underworld, crosses the river Styx where the dragon tailed dog Cerberus guards, allowing all souls to enter but none to leave. This is a misconception, Charon crosses the river Acheron where also Cerebus stands his eternal guard. Also while on this subject, Charon only takes the souls across that are buried properly with a coin (called an obol) that was placed in their mouths upon burial.
If a god gave his oath upon the river Styx and failed to keep his word, Zeus forced that god to drink from the river itself. The water is said to be so foul that the god would lose his/her voice for nine years. The river is not the subject of any story itself but is mentioned in several. These little pieces give a wonderful view of not only the river but the ancient Greeks view of the underworld. From its Adamantine gates to its separate levels of Tartarus and Erebus onto the Elysian fields.
Bron: http://www.pantheon.org/articles/s/styx_river.html