The Cave of the Sibyl and the Gateway to the Underworld

The Cumaean Sibyl depicted in a 17th century painting. (Image source: Public Domain)

In Greek mythology, the souls of the departed travel to the Underworld after death. Sometimes called Hades, in reference to its patron god, the Underworld is described as a dark, sunless region, located either beneath the greatest depths of the earth, or at the outer bounds of the ocean.

In order to access the Underworld, one must cross the Styx – Hades’ most prominent river. The ferryman, Charon, is the one to take the souls which enter the Underworld across the river in exchange for a coin. Those souls who have not received a proper burial, and are therefore unable to pay the ferryman, are left behind.1

A 19th-century interpretation of Charon’s crossing by Alexander Litovchenko. (Image source: Wikimedia Commons / Public Domain)

The Christian equivalent of Hades can be said to be Hell – for both are regarded as the dark counterpart to the bright and holy kingdom of the gods. And, just like Hell, there have been living souls – not just the dead – who have gone searching for the entrance to the Underworld.

Someone who may have succeeded in locating an entrance to the Underworld is Robert Paget.

In the early 1960s, Robert Paget, a British doctor working at a nearby NATO airbase, lived in the ancient Roman town of Baiae. Paget was an amateur archaeologist who excavated in his spare time. It was the enigmatic “cave of the sibyl” described by Virgil and other classical authors which intrigued Paget the most.

The cave, according to mythology, was inhabited by a prophetess who made an unfortunate deal with the god Apollo. As a young woman, she had promised her virginity to Apollo in exchange for as many years of life as there are particles in a pile of dust. However, as she struck the deal she made the mistake of not clarifying that those “years should come with ageless youth, as well”. 2 As such, the sibyl – a Greek term for a prophetess – aged but could not die. For years afterwards she remained in her cave, a cave which – as well as providing her with a place to divine the future – supposedly concealed an entrance to the Underworld. 3

Robert Paget was one of few people who believed that the cave was a real location, and did indeed contain a gateway to Hades.



It had long been said that the Phlegræan Fields, located on the north shore of the Bay of Naples, close to where Paget lived, were where the sibyl’s cave could be found. The Fields certainly have a hellish atmosphere, being situated on top of a collapsed magma chamber of an active volcano. The land is barren and hot, with fire and sulphurous gases leaking from the ground. 4

Sulfur at the Solfatara crater located in the Phlegræan Fields of Italy. (Image credit: Donar Reiskoffer / Wikimedia Commons)

It was near to here, where the Fields vanish beneath the sea, that Paget and a small team of volunteers, over the course of a decade, excavated what turned out to be an incredible tunnel system.

Almost immediately it was obvious to Paget that the tunnels must have had some sort of ceremonial use. The design was unnecessarily complex for a solely practical purpose – notches for oil lamps occurred every yard in the tunnels’ lower levels, far more frequently than would have been required merely to provide illumination. The orientation of the mysterious passageway which marked the entrance to the tunnel system also matched that of the midsummer solstice. 5

Mysteriously, in the deepest and darkest part of the tunnel system, an underground stream – heated almost to boiling point in places – was discovered. With a sulphurous cloud hanging over its hot waters, the stream was reminiscent of classical descriptions of the river Styx. Continuing across the stream, through the heavy and reeking, sulphurous air, Paget and his team found a steep ascending passage, which opened into an antechamber. This room was described as a “hidden sanctum” by Paget. From there, further passageways, with hidden staircases, led off. 6

Throughout the entire system, passageways had been blocked with rubble and rocks, making it difficult to appreciate fully the extent of the tunnels.

All in all, the tunnels at Baiae were found to be immensely complex – with questions as to their purpose and full scope still unanswered. What was the hot, sulphurous stream discovered by Paget under the ground? And why were there tunnels leading to and from it? Had he, as he claimed, discovered the sibyl’s entrance to the Underworld?


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About Laura Rowton 82 Articles
Laura Rowton is a filmmaker and paranormal researcher. In 2019, she released her debut feature documentary on life after death, "In Search of the Dead", which she co-produced with her husband, Erik. Follow her on Instagram for more.