Temple of Apollo, Plutonium

The Anatolian City of Hierapolis was established in Pamukkale ("Cotton-Palace", in Turkish) circa 197–159 BC. Circa 133 BC, the city was annexed to Rome. Hierapolis was rebuilt circa 60 AD, after an earthquake destroyed it circa 17 AD. Hierapolis prospered during the 2nd-3rd centuries AD. In Byzantine times it became the seat of a diocese. Within the Temple of Apollo temenos, an opening was found, to what is considered the oldest local sanctuary of the Plutonium, dedicated to Pluto, god of the netherworld. The Plutonium in Hierapolis was connected to the local cult of Cybele, led by the Galli, the Goddess's eunuch priests. The cult of Apollo adopted the older Plutonium, and both cults were worshipped within the temenos of Apollo. A small cave can be seen next to the Temple remains. Called by the locals 'Cin Deligi' (The Devil's Hole), dangerous Carbon Dioxide gas followed by obnoxious odor is emanating there from subterranean geological activity. In antiquity, only the well trained Pagan priests could enter the original cave, whose opening was man-made. The entrance to the Plutonium was sealed circa 4th Century AD, when pagan activity gradually ceased.