Early Christian tradition states that Philip, along with his daughters, settled at Hierapolis. It is probable that Philip the Apostle (= disciple of Jesus) is the actual person, although a confused tradition suggests that it was Philip the Evangelist (see activities in the book of Acts.).
Tradition states that Philip was martyred and buried here at Hierapolis. On a hill northeast of the city a Martyrium—a memorial that was a focus of pilgrimage—was built in the fifth century AD. The outer walls of this structure form a square and inside of them is an octagonal memorial.
Recently, July 2011, it was announced that the very Tomb of Philip had been discovered. In another release it is stated that the actual Church/Tomb was located on a hill 120 ft. [40 m.] from the Martyrium illustrated here.
For a recent description of the Martyrium of Philip and a discussion of which Philip is being referred to see D'Andria, Francesco. “Conversion, Crucifixion and Celebration.”Biblical Archaeology Review vol. 37, no. 4 (2011): 34–46, 70 and more briefly Mark Wilson, Biblical Turkey — A Guide to the Jewish and Christian Sites of Asia Minor. Istanbul: Yayinlari, 2010, pp. 243–45.