Scientists unravel the mystery of the Roman 'gate to hell'
Tehran (KNA) - Two thousand years ago, ancient tourists flocked to a Greco-Roman temple in Hierapolis, modern-day Turkey, situated on top of a cave once purported to be the gateway to the underworld.
They watched in awe as animals, from birds to bulls, dropped dead at its entrance. The cave, named the "Plutonium" after Pluto, god of the underworld, was thought to belch the "breath of death," killing all those in its reach, except the divinely immune priests who led the animals to sacrifice.
Roman author and natural historian Pliny the Elder described the phenomenon as the "sewer of Charon" -- the mythical ferryman who rowed souls across the River Styx and Acheron and into the depths of the underworld.
But scientists have now provided an explanation for the mystery, and it's not supernatural. Research published by the journal of Archaeological and Anthropological Sciences in February shows that a fissure in the earth's surface, deep beneath the site, emits carbon dioxide at concentrations so high it can be deadly.
Using a portable gas analyzer, Hardy Pfanz and his team of volcanologists found CO2 at levels ranging from 4-53% at the mouth of the cave, and as high as 91% inside -- more than enough to kill living organisms.