Kelkit River in the context of Yeşil River

The Chorokh (Georgian: ჭოროხი Ch'orokhi [t͡ʃʼo̞ɾo̞χi], Turkish: Çoruh, Armenian: Ճորոխ Chorokh, Azerbaijani: Çorox, Greek: Άκαμψις, Akampsis) is a river that rises in the Mescit Mountains in north-eastern Turkey, flows through the cities of Bayburt, İspir, Yusufeli, and Artvin, along the Kelkit-Çoruh Fault, before flowing into Georgia, where it reaches the Black Sea just south of Batumi and a few kilometers north of the Turkish-Georgian border.

In Arrian's Periplus Ponti Euxini, it is called the Acampsis (Greek: Άκαμψις); Pliny may have confused it with the Bathys. Procopius writes that it was called Acampsis because it was impossible to force a way through it after it has entered the sea, since it discharges its stream with such force and swiftness, causing a great disturbance of the water before it, that it goes out for a very great distance into the sea and makes it impossible to coast along at that point.

The Yeşilırmak (Turkish: Yeşilırmak, lit. 'green river'), known as the Iris in antiquity (Ancient Greek: Ἶρις), is a river in northern Turkey. From its source northeast of Sivas, it flows past Tokat and Amasya, crosses the Pontic Mountains and the Çarşamba Plain, reaching the Black Sea east of Samsun after 418 km (260 mi).

Its tributaries include the Çekerek (ancient Scylax) and the Kelkit (ancient Lycus).