ancient-origins October 06 / 2015 Getting your audio player ready... Countless stories, myths, and legends are told about underground cities and subterranean civilizations spread through a vast network of interconnected tunnels across the planet.There are many rumors surrounding these underground portals. We have only to remember the mysterious stories that revolve around the tunnels and galleries of the Cueva de los Tayos in Ecuador, or stories about entrances to underground worlds, supposedly located in the Andes, the Himalayas, the Gobi Desert, Turkey, and even below the Sphinx of Giza.The Hollow Earth Theory and an Expedition to the ArcticThe Hollow Earth theory states that the Earth is a hollow planet with ancient entrances to the subterranean world scattered throughout it, including near both polar caps. This theory has been reported since ancient times and scientists such as Edmund Halley have defended it throughout history.From 1818-1826, the American John C. Symmes passionately supported the theory as well. According to him, there was a subterranean world inside our planet illuminated by a tiny sun, and that included mountains, forests, and lakes. Symmes launched a national campaign aiming to raise the necessary funds to send an expedition to the Arctic to search for an entrance to the subterranean world. He even sent a proposal to the United States Congress, with the intention of getting government assistance to find the entrance to the inner world. Unfortunately for him, he died before the government did allocate funding for his purpose and the expedition departed in 1838, although, in truth, its goals were not so altruistic. In reality it was part of the ploy as world powers were trying to learn the importance of the only land not yet conquered the world: both polar caps. Regardless, commanded by Charles Wilkes, the expedition lasted four years. It served to discover the vast geographical extent of the Arctic, but no sign of a passage into the earth was found.The entrance to the Hollow Earth according to Symmes, as he believed we would see it from the moon with a telescope. Illustration of Harper's New Monthly Magazine October 1882 (Public Domain)Nonetheless, the idea of Symmes remained anchored in the minds of a handful of writers (who tend to love the search for attainment of seemingly impossible dreams.) Thus, Edgar Allan Poe, Jules Verne, and HP Lovecraft, among many others, paid tribute to the fascinating theory of the Hollow Earth.Illustration drawn by Edouard Riou in 1864 from the original edition of "Journey to the Center of the Earth" by the famous Jules Verne. (Wikimedia Commons)Interest in the Hollow Earth theory did not end there. In fact, in twentieth century, with a knowledge of geography and geology of the earth, that was still lacking, there were those who continued trying to access that mysterious world under the earth’s crust. For example, some of the Nazi leaders, the lovers of ancient myths and the occult in Germany, showed a marked interest in these types of theories.History of Hollow Earth TheoryEdmund Halley (1656 - 1742), the English scientist who studied the comet that bears his name, may have been the first to develop a scientific hypothesis about the Hollow Earth. After a series of observations of the Earth's magnetic field, Halley concluded that the anomalies observed could only be explained if the Earth was composed of two spheres: an external solid one and an internal hollow one, each with its own magnetic axis.Edmund Halley with a drawing showing shells of his hollow earth theory. (1736) (Wikimedia Commons)Later on, another American, Cyrus Teed, became convinced that it is mathematically impossible to discern whether we are inside or outside of a sphere, so we could live inside a hollow universe. In the center it would be the Sun, with the planets and stars only appearing bright to us because they reflect sunlight on the surface of the concave Earth. This land was called Koresh - which is the Hebrew translation of his own name, Cyrus. Teed even founded a church and its adherents remained active and defending these ideas until at least 1982.Expedition to Tayos Caves: Never Before Seen Photographs Shed Light on Mysterious Underground NetworkThe Great Pyramid of Giza as a monument of creation - Part 1: EarthUnderground cities and networks around the World – Myths and Reality (Part 1)Ten Amazing Subterranean Structures from the Ancient WorldWith the dawn of the twentieth century other scholars, such as William Reed and Marshall Gardner, also believed they could provide evidence of the existence of an inner world. One of the most curious facts wielded as an argument, made by some Arctic explorers, was that air and water temperatures warmed as they approached the North Pole. Based on these and other observations, they also claimed that mammoths were not extinct, but still inhabiting the interior of the Earth.Mammoth model exhibited at the Royal British Columbia Museum ...