A "gate to hell" from ancient times has been unearthed during an archaeological dig, a member of the team has claimed.
Archaeologists discovered the portal, known as Pluto's Gate, in the ruins of a temple while digging in the city of Pamukkale, which was known to their Roman ancestors as Hierapolis.
The ancient cave, part of a wider complex known in antiquity as Plutonium, acted as a place of worship where animals were sacrificed to the God Pluto - guardian of the underworld. It gained its diabolicial reputation from the mephitic carbon dioxide fumes which emanated from its mouth.
University of Palemo professor Francesco D'Andria is leading the current excavation of the site, which began as long ago as 1957 but has been seriously disrupted by earthquakes over many years.
Speaking to Discovery News, D'Andria revealed that his team eventually found Pluto's Gate after "reconstructing the route of a thermal spring. Indeed, Pamukkale' springs, which produce the famous white travertine terraces, originate from this cave."
D'Andria, who claimed to have uncovered the final resting place of apostle Saint Philip two years ago, also gave some insights into the historical role and rituals of the site.
"People could watch the sacred rites from these steps, but they could not get to the area near the opening. Only the priests could stand in front of the portal.
"We could see the cave's lethal properties during the excavation. Several birds died as they tried to get close to the warm opening, instantly killed by the fumes."
'Anything which goes inside meets death'
Greek writer Strabo penned a description of the place in AD26. He wrote: "This space is full of a vapour so misty and dense that one can scarcely see the ground.
"Any animal that passes inside meets instant death. I threw in sparrows and they immediately breathed their last and fell."
Pluto's Gate lost its status in antiquity when Christianity swept across the Roman empire from the fourth century AD. It remained a popular destination with a small number of pagan pilgrims until the sixth century.
"This is an exceptional discovery as it confirms and clarifies the information we have from the ancient literary and historic sources," researcher Alister Filippini said.