According to mythology, the Acheron is the river crossed by Hermes, the god who conducted the souls into the afterlife. It was a sorrowful procession, so the name of the river is explained by the word “achos” meaning sorrow. According to a different theory, the name is associated with the “echo”, so it was probably derived from the noise of the river in flood. Today the River Acheron with its idyllic landscape and the impressive gorge (impassable until 1994) has been declared an area of particular natural beauty and belongs to the European Natura 2000 network of protected areas. Scientists have recorded 699 species of flora, 19 types of ecosystems, important wetlands with rare species of fauna. Among them is a small fish called govios that only lives in this river.