The Acheron River, approximately 52 kilometers long, belongs to the region of Epirus and crosses the prefectures of Ioannina, Thesprotia and Preveza. Its first springs come from the snow of Mount Tomaros in the Prefecture of Ioannina (1,986 m. altitude) and its other springs come from the mountains of Souli and the mountains of Paramythia in Thesprotia. Important springs are also those of the village of Glyki in Thesprotia. A few kilometers away from Glyki, Acheron flows into the Ionian Sea in the village of Ammoudia in the prefecture of Preveza.
Its name probably comes from the word "achos" (sadness) which means "the river of sadness". According to ancient Greek mythology there Hermes the "psycho transmitter" delivered the souls of the dead to Charon, so that they would end up in the kingdom of Hades. Each soul, passing by Charon's ferry, had to give an obol for the transport to the underworld.