Callichorus or Kallichoros (Greek, Ancient (to 1453);: Καλλίχορος),[1] also called Oxines or Oxinas (Greek, Ancient (to 1453);: Ὀξίνης), was a river of ancient Bithynia. It is mentioned by Pliny the Elder and also by the author of the Periplus of Pseudo-Scylax under the name Callichorus. Under the name Oxinas, it is mentioned by Arrian as draining into the Pontus Euxinus between Heraclea Pontica and Phyllium.[2] Called Oxines by Marcianus, who places its mouth 90 stadia northeast of Cape Posidium.
It is tentatively identified with the modern Ilık Su.