Pluto’s Gateway to Hell: An Ancient Portal to the Underworld Which Killed Victims With Deadly Carbon Dioxide

More than a decade ago, a cave emerged from the ruins in southwestern Turkey. It stood as a witness to a deadly ritual performed by the ancient Romans and Greeks.

Ancient Doorway to the Underworld

Also known as Ploutonion in Greek and Plutonium in Latin, the site is a religious temple dedicated to the god Pluto. It was celebrated as the door to the underworld in Greco-Roman mythology and tradition.

According to historical sources, the site is located in the ancient Phrygian city of Hierapolis in modern-day Pamukkale. The city was a location celebrated as a center of healing, with thermal springs believed to have curative properties that can heal the sick.

The discovery of the cave was made by a team of archaeologists led by classic archaeology professor Francesco D'Andria from the University of Salento. Plutonium was found through the reconstruction of the route of a thermal spring. The finding was announced in April 2013 during an Italian archaeology conference in Istanbul, Turkey.

D'Andria and his team found the remains of a pool, a temple, and a series of steps above the cave. From these steps, people could only watch the sacred sites performed by the priests since they were not allowed to approach the area near the opening.

At sunrise, the divine agents led bulls through the arena towards the doorway. This is where visitors watch the animal struggle and quickly die while the priests remain unharmed.

The pilgrims can also take part in the ritual by purchasing birds and small animals that were released into the arena. As they enter the gate, the animals pass away from the breath of death, leaving the visitors mystified and astonished.

Secrets of the Deadly Mist

According to ancient Greek geographer Strabo, this space is full of vapor so dense and misty that the ground can be scarcely seen. Any animal that goes inside gets killed instantly.

Strabo also noted that only the eunuchs of Cybele were able to enter the deadly doorway without any apparent damage. This is because these people can hold their breath as much as they can. Strabo also noted that the immunity of the eunuchs may be due to divine providence or physical powers used as antidotes against the vapor.

Meanwhile, investigations made by D'Andria and his team suggest that the fatalities are due to the gases from the thermal waters coming from a fissure within the cave. According to D'Andria, the cave was a famous site for incubation rituals. During the ancient times, pilgrims took waters in the pool and received visions and prophecies, probably as hallucinatory effects of fumes released by the phreatic groundwater.

In 2018, a team of researchers examined the gas which was identified as volcanic carbon dioxide. They discovered that its concentration in the atmosphere changed depending on the distance from the entrance.

Within the arena where the animal sacrifices were brought, the levels of carbon dioxide could be between 4-53% depending on their closeness to the mouth of the cave and height above ground level.

The closer an animal or a person is to the floor, the stronger the CO2 concentration is. The priests were able to tolerate this because they stood taller than the bulls and other animals they brought as sacrifice. This means that their noses and mouths remained above the deadly vapor that covered the ground.