Achelous is a river in Greece, known as one of the longest rivers in the country. It flows through the western part of Greece, eventually emptying into the Ionian Sea. The river is significant for its historical and mythological importance, often associated with the ancient Greek god Achelous, who personified the river itself. In mythology, Achelous was known for his ability to change shape and was often depicted as a bull or a serpent. He was involved in various myths, including a famous contest with Heracles over the hand of Deianira. The river and its deity symbolize the power and unpredictability of nature.