For centuries, Hollow Earth conspiracy theorists have tried to prove that there’s a whole other world beneath our own. But first, they need to find the way in.

From time immemorial, people have believed that there is another world lying just beneath the surface of our planet. To a number of cultures—the ancient Greeks for one—it is a dark place filled with the souls of the dead. But most of these early beliefs were metaphorical or mythological in origin.

Modern science holds that the Earth is an unbroken series of layers, crusts, and liquid magma surrounding a dense, hot core made primarily of iron and nickel. But not everyone is convinced. In the 17th century, some of the leading scientific minds of the time came up with a new theory—that the planet is actually hollow. This idea has proved incredibly durable. Even today, there is a small cadre of Hollow Earth believers who are fighting valiantly to validate their ideas through books, websites, meetings and some extremely ambitious travel plans.

“My conception of the Hollow Earth, based on my research is that the shell of the Earth is about 800 miles thick, from the outside to the inner surface,” says Rodney Cluff, author of World Top Secret: Our Earth IS Hollow. He went even further in our phone conversation: half the planet is taken up by surface weight, and then there’s empty space, and then, something else.

“Suspended in the centre of that hollow is an interior sun that is divided by day and night sides,” he says, “The other part of the Hollow Earth theory is that near the North and South pole are substantial openings that lead into the interior.”

We have read the legendary stories about the Nazis who explored the Southern regions of our planet and even creating secret bases in Neuschwabenland. Some also speak about Operation Highjump and Admiral Byrd’s journeys where extremely advanced airships were seen flying around and exploring new territories. Not long ago, we discovered a map of the Third Reich in which there are several secret passages depicted which were used by German U-Boats to access mysterious underground regions, as well as a complete map of both hemispheres and the mysterious kingdom of Agartha.

Possibly the first person to scientifically speculate about a hollow earth was none other than Edmund Halley, of Halley’s Comet fame. Proposed in 1692 as a way of explaining anomalous compass readings, Halley’s theory is that the planet is a series of nested, spherical shells, spinning in different directions, all surrounding a central core. In his estimation, based on readings of the magnetic field and what he knew of the gravitational pull of the sun and the moon on the Earth, this model could account for any inaccuracies in his readings of the magnetic fields of the planet. He also posited that the space between each shell may have had luminous atmospheres capable of supporting life.

In the early 1970s, ESSA, a project belonging to the Department of Commerce of the United States, gave media access to images of the North Pole taken by the ESSA-7 satellite on November 23, 1968. One of the photographs showed the North Pole covered by the usual cloud; the other one showed the same area without clouds, revealing a huge hole where the pole was supposed to be located Between 1946 and 1947, he and his team carried out a large-scale operation called “High Jump”, during which he discovered and mapped 1,390,000 km² of the Antarctic territory. The famous Byrd expeditions first entered in dispute of the hollow Earth theories when several articles and books like Worlds beyond the Poles by Amadeo Giannini claimed that Byrd had not flown over the Pole but inwardly through large holes leading into the Earth.

From Science to Science Fiction

In 1864 Jules Verne published A Journey to the Centre of the Earth, which proposed a weird world inside our own, and while it was not the first work of fiction to propose such a thing (it could be argued that the first such work of fiction regarding the weird world inside of our own is Dante’s poem, Inferno), Verne’s work quickly became the benchmark for such fantasy tales, giving steam to a whole sub-genre of subterranean science-fiction.

Many of these stories used the theories of Halley and Symmes as jumping-off points for tales of weird prehistoric jungles and highly advanced, lost races of humans. The 1892 novel, The Goddess of Atvatabar, or The History of the Discovery of the Interior World, used Symmes’ model as a basis for a tale of a rich interior world inhabited by a race of spiritually enlightened beings. This vision of the Hollow Earth would seem to be one of the prime inspirations of many of the current tropes of modern hollow Earth theory.

Evidence of a “Hollow Earth” is found in the history of countless ancient civilizations.

The Babylonian hero Gilgamesh visited his ancestor Utnapishtim in the bowels of the earth; in Greek mythology, Orpheus tries to rescue Eurydice from the underground hell; it was said that the Pharaohs of Egypt communicated with the underworld, which could be accessed via secret tunnels hidden in the pyramids; and Buddhists believed (and still believe) that millions of people live in Agharta, an underground paradise ruled by the king of the world. So just when you think that these theories could be nothing more than excessive imaginations, you actually come across evidence in ancient history pointing towards the possibility of the world on Earth.

What do you think of the Hollow Earth theory? Is it possible that another world exists, beneath the surface of our planet? And is it possible that there actually is life down there?