High Quality Content by WIKIPEDIA articles The Rioni or Rion River (Georgian: რიონი Rioni, Greek: Φᾶσις Phasis) is the main river of western Georgia. It originates in the Caucasus Mountains, in the region of Racha and flows west to the Black Sea, entering it north of the city of Poti (near ancient Phasis). The city of Kutaisi, once ancient city of Colchis, lies on its banks