Seleucia ad Calycadnum (modern Silifke, in southern Turkey) was a Hellenistic city established in the late 4th or early 3rd century BCE near the mouth of the Calycadnus River, where the river descends from the Taurus Mountains to the Mediterranean coast. This location provided the city with both a fortified stronghold and a valuable harbor town. It was able to command the coastal route between Cilicia and Pamphylia while also controlling access inland along the river valley. Founded by Seleucus I Nicator or his successors as part of the wider network of Seleucid cities, Seleucia was intended to secure the empire’s maritime frontier and promote Greek civic culture in a region of mixed populations.