European geography in just a few clicks.
Longest river in Greece. It rises in the Pindus Mountains and flows south 140 mi (220 km) to the Ionian Sea. Hydroelectric dams harness its waters at Kastraki and Kremasta. In ancient mythology, Achelous was a protean river god, who was vanquished by Hercules.
Find more information on Achelous River. Upgrade to Britannica Online for more on Achelous River.