Irenopolis or Eirenopolis or Eirenoupolis (Greek: Εἰρηνούπολις) was an ancient Roman, Byzantine and medieval city in northeastern Cilicia, not far from the Calycadnus river, also known briefly as Neronias (Greek: Νερωνιάς) in honour of the Roman emperor Nero.

[1][2] The site is a little higher than Hierapolis Kastabala and Anazarbus, on the mountain preventing access to the Cilician plain from the east.

Theodoret of Cyrus confirms that the two names, Eirenopolis and Neronias, apparently refer to the same city.

[3] The name Neronias refereeing to honors bestowed on the city by Nero.

Christianity first came to the area in the 1st century the strategic location through the mountain passes, and the work of St Paul made it an early candidate for missionaries.