flectere si nequeo superos, Acheronta movebo*

The word is also occasionally used as a synecdoche for Hades itself. Virgil mentions Acheron with the other infernal rivers in his description of the underworld in Book VI of the Aeneid. In VII, line 312 he gives to Aeneas the famous saying, flectere si nequeo superos, Acheronta movebo: 'If I cannot deflect the will of Heaven, I shall move Hell.' The Acheron was sometimes referred to as a lake or swamp in Greek literature, as in Aristophanes' The Frogs and Euripides' Alcestis. In Dante's Inferno, the Acheron river forms the border of Hell. Following Greek mythology, Charon ferries souls across this river to Hell.
http://en.wikipedia.org/wiki/Acheron

* se não puder dobrar os deuses de cima, comoverei o Aqueronte