||418 km (260 mi)
The Yeşilırmak (Turkish: Yeşilırmak, "Green River"; classical Greek: Ίρις, Iris) is a river in northern Turkey. From its source north-east of Sivas, it flows past Tokat and Amasya, and reaches the Black Sea at Samsun after 418 km (260 mi).
Its tributaries include the Çekerek (ancient Scylax) and the Kelkit (ancient Lycus).
Strabo's Geographica describes it as flowing through Comana Pontica, the plain of Dazimonitis (Kaşova) (40°17′41″N 36°17′48″E / 40.2947808°N 36.296736°E), and Gaziura (probably modern Turhal) before receiving the waters (40°33′42″N 35°45′34″E / 40.5615797°N 35.7595217°E) of the Scylax, then flowing through Amaseia (Amasya) before reaching the valley of Phanaroea.
- ^ Strabo 12:3:15 at Perseus
Coordinates: 41°22′54″N 36°39′37″E / 41.3816°N 36.6603°E