The Alfeiós or Alpheios (Greek: Αλφειός, Ancient Greek: Ἀλφειός, Latin Alpheus) is the main stream of the Alpheios Valley drainage system, originating on the north slopes of Mount Taygetus, located in the center of the Peloponnesus of Greece, and flowing to the northwest to the vicinity of Olympia, where it turns to the west and, after being impounded by the Flokas Dam, empties into the Gulf of Kyparissia of the Ionian Sea south of Pyrgos.
