Kizil Irmak, i.e. “Red River” (anc. Halys), the largest river in Asia Minor, rising in the Kizil Dagh at an altitude of 6500 ft., and running south-west past Zara to Sivas. Below Sivas it flows south to the latitude of Kaisarieh, and then curves gradually round to the north. Finally, after a course of about 600 m., it discharges its waters into the Black Sea between Sinope and Samsun, where it forms a large delta. The only important tributaries are the Delije Irmak on the right and the Geuk Irmak on the left bank.