The plain is watered by the Cydnus (Tarsus Chai), the Sarus (Sihun) and the Pyramus (Jihun), each of which brings down much silt.
Through it ran the great highway, between the east and the west, on which stood Tarsus on the Cydnus, Adana on the Sarus, and Mopsuestia (Missis) on the Pyramus.
The Cydnus (Tersous or Tarsus Chai) is formed by the junction of three streams that rise in Mt.
The Cydnus is liable to floods, and its deposits have covered Roman Tarsus to a depth of 20 ft.
Thus the Ak Geul supplies the Cydnus, and the Beishehr, Egirdir and Kestel lakes feed the rivers of the Pamphylian plain.