Achelous

Achelous is a river god in Greek mythology. As the deity of the largest river in Greece, he was considered the chief of the Greek Potamoi and father of Sirens. He is the son of Oceanus and Tethys. His name, though of a pre-Greek origin, was later thought to mean "he who washes away care".

In Mythology
Achelous was a suitor of Deianeira, daughter of King Oeneus of Aetolia. Another suitor, Heracles fought him for her. Achelous turned himself into a serpent and later, a bull but Heracles defeated him and broke one of his horns, giving it to the nymphs. It later became the Cornucopia. In Ovid's Metamorphoses, Achelous relates this tale to Theseus while hosting him in a cave.

Analysis
According to Strabo, the noise of the river's water resembled a bull's voice. It meandering nature gave rise to the serpent component of the myth. Heracles confined the raging river to a smaller embankment, thus "defeating" it and gaining large tracts of fertile land (hence the cornucopia).

The River Today
The river has its origin in the Pindus mountains. It is 220 km long. Its average annual discharge is 7,800,000,000 m3 of water. 82px-Acheloos_river_map.jpg|Route of the river Acheloos_river_narrows_02.jpg|The Achelous river at a narrow point 

Acheloos