The centuries-old mystery of the mysterious “Gate of Hell” in the Hierapolis Ancient City in Pamukkale has been solved thanks to modern science.
The centuries-old mystery of the “Gate of Hell” in the Hierapolis Ancient City in Pamukkale has been solved thanks to modern science.
Travertines in Pamukkale are among the most popular tourism spots in Turkey. This unique structure was formed by the slow accumulation of limestone cliffs left behind by the bubbling of mineral-rich natural spring water over 400,000 years.
As this natural spring water flows down the slope, it is purified from the gases in it. This leaves behind a bright white deposit of calcium carbonate about 3 kilometers long, 160 meters high.
A similar structure is found in Huanglong in China and Yellowstone National Park in the USA.
However, the common view is that Pamukkale, which is on the UNESCO World Heritage List, is home to the most magnificent travertines.
Pamukkale was visited by 2.5 million tourists a year before the pandemic. However, most of these tourists were watching this fascinating sight without being aware of a much bigger mystery.
However, the ruins of the ancient city of Hierapolis, located on the top of Pamukkale’s white cliffs, have a much more fascinating attraction.
B.C. Founded by the Attalos Dynasty in Pergamum at the end of the 2nd century, Hierapolis passed into the hands of the Romans in 133 AD.
It turned into a thriving spa town under ancient Roman rule. By the 3rd century, visitors from all over the Empire flocked here to admire this enchanting sight and bathe in the waters that are said to be healing.
Centuries later, this city is still a favorite with visitors, with its impressive arched entrance gate, colonnaded main street and beautifully restored amphitheater built of travertine shining golden under the hot Anatolian sun.
South University of CaliforniaRoman Empire expert archaeologist Dr. “Thermal waters are probably one of the main reasons the city was founded,” says Sarah Yeomans:
“In the mid-2nd century, Hierapolis was, in my estimation, a beautiful and vibrant spa center with a more dynamic and diverse population than many other places, thanks to visitors from different places.”
However, despite all these beauties, Hierapolis was also known in Roman times for a more sinister reason.
According to rumors, the “Gate of Hell” that opened to the underground was also located here. Again, according to these rumors at that time, the poisonous breath of the three-headed hellhound Kerberos flowed from the ground in the underground, which was entered through this door, and the innocents were sacrificed to Hades (Pluto), whom he accepted as a god.
For this reason, the Temple of Apollo was built here, next to the Plutonium, which was called the “Gate to Hell”. Now those who came here began to pay the priests in the temple to make sacrifices to the gods on their behalf.
Leading writers of the time, such as Plinius the Elder, one of the famous historians of the ancient Roman period, and Strabo, the Greek geographer, described these sacrificial rites as “a gruesome spectacle”. A priest would take an animal such as a lamb or a bull into the temple, and the animal would die on the spot, as if by divine intervention, and the priest would come out alive.
Strabo wrote, “I threw the sparrows inside, they gave their last breath and fell to the ground,” by not hiding his surprise at the rite he witnessed in the 13th volume of the 17-volume Encyclopedia of Geography.
When you visit the Temple of Apollo today, it’s hard to imagine that these dramatic scenes are real. Today it is a peaceful place surrounded by a rectangular enclosure filled with clear water about 25 centimeters deep, with mineral foams floating around it, and an arched entrance on one side.
There are steps on this place where those who want to watch the surroundings can sit and a copy of the statue of Hades (Pluto).
When I visited this place, I never thought that this place could be a place of death centuries ago. On the contrary, I believed that these were rumors and legends. How could the clergy with them survive when animals entering the same place died?
These questions I asked were also the ones that occupied the minds of Volcano biologist Hardy Pfanz, who studies the gases released during geological processes at the University of Duisburg-Essen in Germany.
Pfanz said, “When I read what the ancient authors wrote, I began to wonder if there was a scientific explanation for what was happening. Could this Hell’s Gate be a volcanic vent?” says.
Pfanz visited Pamukkale in 2013 to test his theory:
“We weren’t too sure what we were going to find. It could be all made-up legends. It could have been nothing. But we certainly didn’t expect such a quick response.”
Pfanz quickly grasps what’s actually going on as soon as he visits here:
“We saw dozens of dead animals around the entrance: mice, sparrows, blackbirds, many insects, wasps, etc. So we knew right away that the stories told were true.”
Pfanz tested the air around the structure with a portable gas analyzer and found very high levels of carbon dioxide as a result of the test.
Normal air contains only about 0.04 percent of carbon dioxide. However, Pfanz said he was shocked to discover that the rate around the temple had reached an astonishing 80 percent. “Your exposure to 10 percent carbon dioxide for just a few minutes is life-threatening. The amount here was really lethal,” says Pfanz.
This is due to the same geological system whose extreme carbon dioxide levels also spawn the region’s hot springs and travertines.
Pamukkale is located in an active tectonic fault line region that is 35 kilometers long. One of these lines passes directly through the city center and extends to the Temple of Apollo.
Yeomans, of the University of Southern California, said: “I almost certainly think that the choice of plutonium’s location was directly related to the seismic gas vents found here. Given that the underworld and its associated gods and myths played an important role in the beliefs of that period, they believed it was under their feet. It is plausible that they built temples at the points where they thought they were closest to the world.”
Being so close to the forces of nature came at a price. This active fault line caused earthquakes in the 17th and 60th AD, and in the 17th and 14th centuries AD, that razed the city to the ground. As a result of these demolitions, the Ancient City of Hierapolis was abandoned.
However, although this mystery had largely been solved, there was another issue that continued to puzzle Pfanz’s mind: If this is such a dangerous area to threaten human life, then why could the clergy who entered the temple survive?
Following this question, Pfanz visited the Ancient City of Hierapolis once again the following year. This time he measured at different times:
“During the day, when it’s warm and sunny, we noticed that carbon dioxide dissipates quickly. However, because carbon dioxide is heavier than air, it builds up on the ground when it’s colder at night, creating a deadly gas lake at ground level.”
From these findings, Pfanz concluded that animals with noses closer to the ground quickly suffocated in this poisonous cloud, but taller clergy survived because they exhaled lower carbon dioxide.
So was this sacrificial ritual actually a ruse to make money, or did the priests really believe they were communicating with the gods?
To this question, Yeomans replied, “There is no doubt that the Plutonium at Hierapolis was very, very important. However, it is difficult to be sure whether the clergy really understood what was going on. Some may have attributed their survival to the grace of the divine, while others He may also have regarded it as a mysterious but natural state that can be observed or at least predicted to a certain extent.”
Today Hell’s Gate is built with bricks. A walking path has been built around it so that visitors can see this historical structure without being exposed to high carbon dioxide.
But even in its modern form, it is exciting to walk in the footsteps of Greek and Roman pilgrims and to look down on this magnificent place where mythology and earthly reality meet, where ancient gods reach out and touch people’s lives.
“I was standing right in front of the arch when I first realized that the legendary breath of Kerberos was actually carbon dioxide. At that moment, I realized that we had solved this ancient mystery; it was a really cool feeling,” Pfanz describes.