Kastabala-Hierapolis was one of the most significant cities in ancient Cilicia. It is today situated 12 km north-northwest of Osmaniye province, in the centre of the villages of Kesmeburun, Bahçe and Kazmaca. The city was founded near the Ceyhan (Pyramos) River and dominates a small plain. It is encircled by a wall constructed in the 4th century AD, with the majority of the buildings situated on the northern and eastern slopes of a small valley, dominated by Castle Hill. Hierapolis was first mentioned on coins minted during the reign of Antiochus Epiphanes IV, one of the Seleucid kings. The city was named "Hierapolis" by Antiochus IV, meaning "holy city," in reference to the goddess Artemis Perasia, who was worshipped in the city for many years. Kastabala became one of the few major cities in Cilicia during the Roman Empire, but lost its importance in the Middle and Late Byzantine periods and was abandoned after the destruction of the Crusades. The ruins that remain in the city are mostly from the Roman period. In terms of urban planning, the principal axis of the settlement is the west-east running colonnaded street. The theatre, baths, shops, northern and southern churches were constructed along this street. The medieval castle is situated on a rocky hill that was utilised for defensive purposes.