Decades after the last of their worshippers moved on to new gods, the Old Gods find themselves still hungry for the occasional sacrifice, or so it seems. In Turkey, the Gates to Hell in the remains of Hierapolis seem to be still claiming lives in the name of Pluto, but why?

An ancient site of worship

The city of Pamukkale, Turkey, is known primarily for its beautiful blue and white travertine hot springs. The “Cotton Castle” from which the town gets its name is the base of an ancient manmade site of worship. Hierapolis sat atop the hot springs and provided entertaining spaces, such as an amphitheater and a gymnasium, as well as places of worship. One of these holy sites was the Plutonium, a shrine to the god of the underworld.


Though the site was walled off during Christian times, recently, the shrine has been reopened, and its sacrifices have started back up. Have the Old Gods returned, or is something else going on?

Uncovering the work of the gods

Scientists, intrigued by the number of deaths taking place within the shrine, ran some tests on the area to reveal the cause. Pamukkale sits atop an active volcanic vent whose gases feed and warm the hot springs at the surface. Those same vents are responsible for the mysterious deaths at the Plutonium. Carbon dioxide gas seeps out from the cracks, or fissures, in the Earth’s crust along these volcanic vents. Since it weighs more than oxygen, the CO2 settles down closer to the ground, creating a deadly layer of oxygen-free air that suffocates any animal that passes through it and tries to take a breath.

New York Post

During Hierapolis’ heyday, sacrifices were often made at the Plutonium to prove the strength of its God. Birds and other small animals were sold to be released into the chamber, from which they would never return. It also served as a chamber of tests for Cybele priests who would crawl through the tunnels within the shrine to prove their immunity to the deadly gases within and claim that the divine will of the gods kept them alive.

A silent killer

While the deadliest parts of Plutonium are deep within it, vapors of carbon dioxide are still present at the mouth of the tunnel, which then leads deeper down. The fumes are potent enough to kill birds that fly too close to the opening of the cave. Within, carbon dioxide levels vary from 4 percent to 53 percent, changing with the depth of the chamber.


While you may survive a view from the top, venturing into the Gates of Hell may well be the last thing you ever do. The misty vapors from the volcanic fissures make it difficult to see the ground, and deep within the chamber, a deadly lake of carbon dioxide waits to suffocate anyone unfortunate enough to wade into it.