Aliakmonas (Aliakmon) is a river in western Macedonia. It is the longest river in Greece and is located entirely in Greek territory with a total length of 297 km. The river flows from the mountains of Verno, Grammos and Voio, at the country's borders with Albania and flows into the Aegean Sea between Thessaloniki and Katerini, making a delta of 40.000 hectares.
Τhe name Aliakmon is a complex and comes from als (salt, sea) and akmon (anvil). According to Greek mythology Aliakmon was one of the river gods, son of Oceanus and Tithys, in obsessive-beloved allegorical anthropomorphic conception of the ancient Greeks on the geological upheaval after the flood of Deucalion.
An ancient tradition says that what sheeps drank water from Aliakmonas changed color and became white. This tradition is confirmed by a recording of the Latin writer Pliny (AD 23-79), which translated from Latin, it says: "Also in Macedonia, those who wants to have white sheeps must go to Aliakmonas, those who wants to have black sheeps must go to Axios".
(Summary from Wikipedia and translation by C. Theodorou)