Hierapolis Ancient City is an ancient metropolis located on hot springs in classical Phrygia in southwestern Anatolia, near the modern city of Denizli, Turkey. Established around 200 BCE, it was sited on the ancient road which traversed the Aegean region from Sardis. Hierapolis was famous for its sacred hot springs, whose vapors were associated with Pluto, god of the underworld. The city also housed a significant Jewish community and had religious prominence as the site of Philip the Apostle's martyrdom. Architecturally, Hierapolis boasts well-preserved Roman ruins, including a grand necropolis with sarcophagi, an impressive amphitheater with a stunning view, and remnants of a colossal ancient temple. In the 2nd century, it was refashioned as a spa city with baths and other structures harnessing the thermal waters. Hierapolis was recognized as a UNESCO World Heritage Site alongside Pamukkale's travertine terraces.