Silifke (Σελεύκεια, Seleukeia, Seleucia ad Calycadnum) is a town and district in south-central Mersin Province, Turkey, west of the city of Mersin, on the west end of Çukurova.
Silifke is near the Mediterranean coast, on the banks of the Göksu River, which flows from the nearby Taurus Mountains, surrounded by attractive countryside along the river banks.
Silifke was formerly called Seleucia on the Calycadnus — variously cited over the centuries as Seleucia [in] Cilicia, Seleucia [in, of] Isauria, Seleucia Trachea, and Seleucia Tracheotis —. The city took its name from its founder, King Seleucus I Nicator. The ancient city of Olba (Oura) was also within the boundaries of modern-day Silifke. The modern name is derived from the Greek Σελεύκεια, which is pronounced Selefkia in Greek.
Located a few miles from the mouth of the Göksu River, Seleucia was founded by Seleucus I Nicator in the early 3rd century BC, one of several cities he named after himself. It is probable that there were already towns called Olbia (or Olba) and Hyria and that Seleucus I merely united them giving them his name. The city grew to include the nearby settlement of Holmi (in modern-day Taşucu) which had been established earlier as an Ionian colony but being on the coast was vulnerable to raiders and pirates. The new city up river was doubtless seen as safer against attacks from the sea so Seleucia achieved considerable commercial prosperity as a port for this corner of Cilicia (later named Isauria), and was even a rival of Tarsus.
Cilicia thrived as a province of the Romans, and Seleucia became a religious center with a renowned 2nd century Temple of Jupiter. It was also the site of a noted school of philosophy and literature, the birthplace of peripatetics Athenaeus and Xenarchus. The stone bridge was built by the governor L. Octavius Memor in 77 AD. Around 300 AD Isauria was established as an independent state with Seleucia as the capital.
Early Christian bishops held a Council of Seleucia in 325, 359, and 410.