The Acheron is a very large and wide river that circles around the vestibule of Hell. On the other side of Acheron lies Limbo and the court of King Minos. Charon ferries the shades of the damned across the Acheron. A dreary fog hangs over the water, and lightning strikes light up the sky above it. On its shores lie those who lived with neither infamy or praise, denied entry into the Inferno or Paradise.
See Charon for more details.