Calycadnus basin

Göksu River
Göksu at Silifke Castle
Country	Turkey
Basin features
Main source	Taurus Mountains
River mouth	Mediterranean Sea near Silifke 36°17′45.6″N 34°2′52.8″E / 36.296000°N 34.048000°E / 36.296000; 34.048000Coordinates: 36°17′45.6″N 34°2′52.8″E / 36.296000°N 34.048000°E / 36.296000; 34.048000
Physical characteristics
Length	260 km (160 mi)

The Göksu (Turkish for "blue water" also called Geuk Su, Goksu Nehri; medieval Latin: Saleph, Ancient Greek: Καλύκαδνος Calycadnus) is a river on the Taşeli plateau (Turkey). Both its sources arise in the Taurus Mountains—the northern in the Geyik Mountains and the southern in the Haydar Mountains. Their confluence is south of Mut.

The river is 260 km long and empties into the Mediterranean Sea 16 km southeast of Silifke (in Mersin province). The delta of the Göksu, including Akgöl Lake and Paradeniz Lagoon, is one of the most important breeding areas in the Near East; over 300 bird species have been observed. Among others, flamingos, herons, bee-eaters, kingfishers, gulls, nightingales and warblers breed here. The endangered Loggerhead Sea Turtle (Caretta caretta) lays eggs here.

Due to demand for summer vacation apartments by the locals, and since necessary precautions are not taken and public attention is minimal in this part of Turkey, the ecosystem around Akgöl Lake and Paradeniz Lagoon is in heavy danger.

In 1190, while on the Third Crusade, Emperor Frederick Barbarossa drowned in the river, then known by his Latin name Saleph and loacated within the Armenian Kingdom of Cilicia. The crusaders had reached Asia Minor in March, where the emperor continued his campaign to the Holy Land. Having plundered the city of Konya and defeated the forces of the Sultanate of Rum at the Battle of Iconium, his forces arrived on the banks of the river on June 10.