"NARRATOR:" "A temple of the dead in the Yucatán... an underground city in Turkey... and a South American cave said to contain a treasure from beyond the stars." "For centuries, people have told tales of caves and tunnels deep inside the Earth." "Subterranean passageways that lead to lands of gods and monsters." "But is there a surprising truth behind these legends?" "LINDA HOWE:" "I have stood in front of drawings on the rocks and wondered, "Am I looking at a extra-terrestrial biological entity?"" "NARRATOR:" "Could there really be mysterious places far beneath our feet?" "Places whose origins might not be of this Earth?" "PHILIP COPPENS:" "There were certain aspects of the caves for which geology could not provide an answer." "NARRATOR:" "Millions of people around the world believe we have been visited in the past by extraterrestrial beings." "What if it were true?" "Did ancient aliens really help to shape our history?" "And if so, should we be looking for proof of their existence not in the heavens above but in mysterious worlds deep beneath the surface?" "Bordered on the north by the" "Black Sea, and by the Taurus" "Mountains to the south, lies" "Cappadocia in central Turkey." "Here, wind and water have sculpted strange shapes out of the soft volcanic rock... rock which ancient peoples once turned into small, primitive dwellings." "In more recent years, the site has seen the construction of more modern structures." "But in 1963, a simple home renovation in the town of" "Derinkuyu led to an extraordinary discovery when a cave wall was opened, revealing a passageway to an underground city thousands of years old and more than 280 feet deep." "GIORGIO TSOUKALOS:" "I've been there on multiple occasions, and it's incredible because there's" "13 stories that go deep into the ground, with ventilation shafts and 15,000 little shafts that bring air to even the deepest of levels." "NARRATOR:" "Incredibly, the number of rock rooms that were found could hold over 20,000 men, women and children." "There was even evidence of religious centers, storerooms, winepresses and stables for livestock." "JOHN BRANDENBURG:" "Oh," "Derinkuyu would've been a massive undertaking for anyone, even in modern times with modern equipment." "But in those days, it would've been, um... stupendous." "Equal to the pyramids." "At Derinkuyu, because of the softness of the stone, you had to be very careful that you provided enough pillar strength to support the floors above, otherwise you'd have catastrophic cave-ins." "Surprisingly, there's no evidence of any catastrophic cave-ins, so they were apparently extremely clever and knew their material." "We're talking deep antiquity." "It is mind boggling to understand how they could've done this." "Perhaps they had help from some other civilization." "NARRATOR:" "But just who built this massive underground city?" "And what mysterious force drove them to live underground?" "DAVID CHILDRESS:" "Why would people want to live deep underground in these weird caverns like that?" "It seems kind of scary, really." "NARRATOR:" "According to many archaeologists and scholars," "Derinkuyu was most likely intended to serve as a temporary shelter from invasion... built around 800 B.C." "by the Phrygians, a Bronze Age people related to the Trojans." "Others believe it was built by the Hittites, a warrior people mentioned in the Bible who flourished hundreds of years earlier." "But could the underground city be even older?" "According to ancient astronaut theorists, it is, perhaps by many thousands of years." "DAVID WILCOCK:" "The" "Cappadocia region of Turkey was part of the Zoroastrian" "Empire, which was Persian in nature." "And it's one of the oldest religious traditions on the face of the Earth." "NARRATOR:" "The Zoroastrian religion... an ancient faith based on opposing forces of good and evil... is widely believed to have influenced both Hinduism and" "Judeo-Christianity." "Founded sometime before the sixth century B.C., its chief god is the creator, Ahura Mazda." "And in the second chapter of the Zoroastrian sacred text, the Vendidad, Ahura Mazda saves mankind from a worldwide environmental disaster... much like the story of Noah in the" "Hebrew Testament." "TSOUKALOS:" "The great prophet" "Yima, he was instructed to build a kind of underground refuge similar to Derinkuyu by the sky god Ahura Mazda." "NARRATOR:" "According to the sacred texts, Yima built a multilevel underground city to protect a select group of people and animals, not from a flood but from a global Ice Age." "The Vendidad calls this "the evil winters."" "According to many mainstream climatologists, the last Ice" "Age peaked around 18,000 years ago and ended around 10,000 B.C." "Is it possible that Derinkuyu was built as a refuge from a devastating global winter?" "TSOUKALOS:" "Since you cannot carbon date stone, it's anybody's guess how old" "Derinkuyu really is." "And my question is: if we have a Zoroastrian story that's very similar, could it be that both that place and Derinkuyu are much, much older than what we've believed so far?" "NARRATOR:" "But if Derinkuyu is in fact the underground city that Ahura Mazda told his followers to build, could there be a stunning truth behind the legend?" "If so, who or what was the god" "Ahura Mazda?" "WILCOCK:" "Ahura Mazda does appear to be responsible for the management of whatever is happening here on Earth." "There are various ways to read this, one of which is that it does represent some sort of higher universal form of consciousness." "But another is that it would represent an overseeing extraterrestrial intelligence." "JASON MARTELL:" "Several sacred texts from antiquity speak of knowledge given to mankind from extraterrestrials, but also known as gods from antiquity." "NARRATOR:" "Could the sky god" "Ahura Mazda really have been an advanced being from another world?" "If so, did he provide the technology needed for his followers to build this complex labyrinth as protection from environmental disaster?" "Or is there possibly a more ominous reason for Derinkuyu's existence?" "Some say a clue lies in the underground city's unusual security system: 1,000-pound doors on rollers that allow them to be moved by a single person, but only from one side." "BRANDENBURG:" "The Derinkuyu doors... they're very cleverly constructed." "You can basically only open it and leverage it from the inside." "TSOUKALOS:" "So obviously, whoever inhabited Derinkuyu was hiding from someone or something." "NARRATOR:" "According to the ancient Zoroastrian texts," "Ahura Mazda soared through the sky in a divine chariot and waged war against his eternal enemy, Angra Mainyu, the demon of destruction." "But could this really be-as many ancient astronaut theorists believe... a depiction of two extraterrestrial forces battling over control of the" "Earth and its resources?" "TSOUKALOS:" "The aerial enemies were extraterrestrials, because they were the ones who had the capability of flight." "They had access to those types of machines that we can read about in every single ancient culture around the world." "WILCOCK:" "When you look at the Zoroastrian tradition, you also see clear evidence that there was some sort of extraterrestrial battle going on between warring factions." "Therefore, it is certainly possible that the original caves may have been used as shelters against possible aerial bombardment from extraterrestrials that were warring with each other during that time." "TSOUKALOS:" "Derinkuyu was built out of fear of an aerial enemy, because if something flies over you very, very fast, you can't see the ventilation shafts." "Some suggest 30,000 people used to live underground at" "Derinkuyu." "NARRATOR:" "During recorded history, many different peoples did in fact hide in the underground city of Derinkuyu to escape everything from desert raiders to Roman legions." "But some experts wonder whether such conventional attacks can really explain why Derinkuyu was built in the first place." "TSOUKALOS:" "If it were an enemy that was on horseback, it would be easy for them to just smother everyone inside by just closing all the ventilation shafts." "BRANDENBURG:" "We had the phrase in the Defense" "Department studies that I participated in, that a cave is a grave to a well-prepared adversary." "Once you find it, it is highly vulnerable." "NARRATOR:" "But did the people of Derinkuyu really go underground to avoid becoming casualties in an extraterrestrial battle in the skies?" "And, if so, might there be other such cities from the distant past?" "According to ancient astronaut theorists, there are." "And they can be found much nearer to home... deep in the caves of the American Southwest." "NARRATOR:" "The majestic mesas and rugged mountains of the" "American Southwest are home to many native peoples, including the Navajo, Zuni, Pueblo, Hopi and Apache." "These tribes have many different beliefs, but their creation myths all share something quite remarkable." "JAY VIGIL:" "When we talk about our origin, you know, you hear the stories about us coming down from Alaska through the Bering" "Strait." "But what we believe is we came up from the ground." "CHILDRESS:" "The Apaches and other Pueblo Indians, such as the Zunis and the Hopi Indians, all have this legend that they emerged from some underground world into today's world." "NARRATOR:" "In some legends, the Southwestern peoples went back underground for safety." "The Hopi of Arizona say their ancestors escaped a deadly storm of falling stars with the help of the Snake People, who took them to shelters deep in the Earth." "Another Hopi legend speaks of the Ant People who protected them from storms of fire and ice." "CHILDRESS:" "The Hopi Indians survived cataclysms by living in this underground world with the Ant People for a certain period of time, and then eventually they emerged from the underground world back into the surface world." "NARRATOR:" "Ant People?" "Snake People?" "Could these stories be based on ancestral tales of people actually living underground... possibly during the last Ice" "Age?" "Or could the ancestors of today's Southwestern tribes have taken refuge in sub-surface dwellings similar to the underground city of" "Derinkuyu in Turkey?" "If so, over the centuries, might they have developed physical traits..." "like large eyes and fingers... that made them more closely resemble actual Earth-dwelling creatures?" "TSOUKALOS:" "The shamans, and the elders of Native Americans, they will tell you that before these people were able to emerge out of Planet Earth, they were brought here by the star-people, the star-gods, which arrived from outer space." "HOWE:" "I have stood in front of what are called the Ant" "People and some of the very strange, large-eyed drawings on the rocks and wondered, "Am I looking at Native American interpretation of what today is called a extraterrestrial biological entity?"" "TSOUKALOS:" "If extraterrestrials were here in the remote past, there are multiple species out there, is it possible that they might've looked lizard-like and ant-like?" "And the answer is yes." "NARRATOR:" "Is it possible that these underground creatures of" "Native American legend were actually alien visitors?" "If so, could some of them still be living beneath the surface of the Southwestern desert?" "For decades, stories of encounters with UFOs and alien beings have been told among the people of New Mexico's" "Jicarilla Apache Reservation." "Some of the aliens in these stories bear a strange resemblance to the ancient tales of the ant-like and snake-like beings from the Hopi legends." "RICHARD VIGIL:" "There is things up here that no one can explain." "NARRATOR:" "The Jicarilla" "Apache Reservation is located next to the small town of Dulce, nestled in the shadow of the over 9,000-foot-high Archuleta" "Mesa." "CHILDRESS:" "It is from this mesa and mountain that people claim they have seen" "UFOs flying out of the mountain." "GERALDINE JULIAN:" "It was a spaceship we saw right there." "And it was big..." "like maybe the size of a football field." "And then we seen this dome on top that was all glassed in." "And then my husband was looking at it with the binoculars and he saw two small people." "Well, we don't know what it is." "If we stayed here and they came down, I don't know what they would have done to us." "NARRATOR:" "Could the native tales of spaceships and strange creatures be true?" "Some UFO researchers and conspiracy theorists believe that these eyewitness accounts are not only true, but are evidence of a secret collaboration between underground aliens and the U.S." "military." "BILL BIRNES:" "The amount of military traffic over Dulce, the unmarked helicopters, the black helicopters, the heavy-duty" "Chinooks." "All these helicopters spend a lot more time in Dulce than they should if nothing were going on here." "Among the stories that we've heard from the Jicarilla Apache is that they discovered vents, actually right here on the Mesa." "JAY VIGIL:" "Awhile back, when my brother was still alive, we used to come up here in the back, and he showed us this shaft and that thing was bigger than... bigger than me." "But we walked in, and I didn't want to go any further." "BIRNES:" "The vents were here maybe 25 years ago." "You'd hear strange noises." "Groans." "Sighs." "Human groans." "And this lent a lot of credence to stories that human beings were being vivisected, experimented on." "And thus the legend of strange creatures and strange noises coming out of this mesa grew and expanded." "NARRATOR:" "Aliens living underground." "Strange, secret government cover-ups." "Could Native American legends of underground beings help unearth the truth behind these incredible stories?" "Some think the answer might be found deep beneath the surface of North America, but others believe the truth lies hidden in a mysterious cave... thousands of miles to the south." "A cave that hides proof of alien visitors who journeyed beyond the stars." "NARRATOR:" "South America." "The Andes Mountain range in" "Ecuador." "For thousands of years, this rain forest... high on the eastern slopes... has been the land of the Shuar, headhunters who are fiercely protective of their homeland, and its secrets." "And of all the Shuar's secrets, perhaps none has been so carefully guarded as the location and entrance of the cave of Tayos." "But why?" "Perhaps the answer can be found in the story of an Italian" "Catholic missionary named" "Father Crespi, who lived in the region in the middle of the last century." "ERICH VON DANIKEN:" "Father" "Paolo Carlo Crespi." "He was loved by the Indians." "He helped them without, uh, asking for money." "And the Indians made him some presents." "NARRATOR:" "But what was unique about the "presents" or gifts given to Father Crespi was that they often took the forms of elaborately-carved artifacts... some made of gold or other precious metals." "Often these objects featured elaborate carvings and symbols... not known to be associated with the Shuar culture." "In his 1973 book, Gold of the" "Gods, ancient astronaut theorist Erich Von Daniken wrote of Father Crespi's incredible collection... which he believed to come from the cave of Tayos and which were, in his opinion, treasures from an unknown and highly-advanced culture." "The startling questions posed in Von Daniken's book soon inspired Scottish explorer" "Stanley Hall to try and solve the mystery himself." "In 1975, Hall traveled to" "Cuenca to see Father Crespi's collection with his own eyes." "STANLEY HALL:" "I had for years been researching South America as the missing page of pre-history." "I first heard of the Tayos" "Caves was in Erich von Daniken's book and followed it through from there." "VON DANIKEN:" "And one of the presents which the old priest received is a tablet with 36 writings." "It's metallic tablet." "No one until today was able to translate these writings." "NARRATOR:" "In 1976, Stanley" "Hall mounted an expedition of more than 100 people to explore Tayos." "Among them was American astronaut Neil Armstrong, the first man to walk on the Moon." "Entering the cave through a jungle entrance known to the" "Ecuadorian Army, the explorers were fascinated by what they encountered... especially large areas that appeared to have been excavated by someone... or something." "STANLEY HALL:" "The head of the" "British geological group, Dr." "Brian Kelly, in 1976, he admitted that it was difficult for him to explain the actual large doorways that you see in these caves." "NARRATOR:" "Although Stan" "Hall's expedition did find a tomb chamber with items dating to 1500 BC..." "MAN:" "A ring!" "A stone ring!" "NARRATOR: ...the expedition found no treasure and no trace of anything that looked like the artifacts in Father Crespi's collection." "But if Tayos was not the secret origin of Father Crespi's amazing collection, where did it come from?" "Undaunted, Hall didn't give up his search." "15 years later, in 1991, the explorer tracked down an" "Ecuadorian named Petronio" "Jaramillo who claimed to have entered the cave of Tayos through a secret entrance back in 1946." "STANLEY HALL:" "And apparently," "Petronio had visited this cave for the very first time when he was very young." "When he was in his teens." "He said that he had to dive underwater, go in... in this underwater tunnel, and then come up." "NARRATOR:" "Jaramillo told Hall he wandered through chamber after chamber of ancient relics, including a vast room of books made from gold and other metals... books with unrecognizable writing... possibly like that on one of the metal tablets in Father Crespi's" "collection." "STANLEY HALL:" "The other things looked like formulas, and so on, and so on." "So it was one spectacular statement after another." "(bats squeaking)" "COPPENS:" "Some argue whether or not an ancient civilization had come down to Earth and had used this cave system to leave certain artifacts of their civilization behind for us to recover." "NARRATOR:" "Unfortunately, before he could guide Stanley" "Hall to the underwater cave entrance, Petronio Jaramillo died, taking the secret to his grave." "Stanley Hall himself died in 2008 before he was able to renew his search for the so-called metal library." "Fortunately, Stanley Hall's daughter Eileen has decided to continue her father's work." "EILEEN HALL:" "Unless we find this treasure, unless we can see, translate the writing, it's still a big question mark over who wrote it, why they put it there and who put it there." "NARRATOR:" "But when Eileen" "Hall began to look for the location of Father Crespi's original artifacts, she learned that much of the priest's collection had mysteriously vanished shortly before his death in 1982." "But why?" "Had Crespi's artifacts fallen prey to thieves?" "Or might the Shuar have taken their treasure back into the cave where they found it?" "Whatever the answer, Eileen" "Hall has continued to research other artifacts from elsewhere in Ecuador." "And like Father Crespi's objects, some seem to have uncanny resemblances to other cultures that, according to mainstream archaeology, ancient" "Ecuadorians could not have had any knowledge of." "EILEEN HALL:" "This collection is made up of what my father believed to be the formative cultures of Ecuador." "This is from the coastal culture from 600 BC to 1600 AD, and this is very humanlike, but at the same time, some features have been exaggerated." "Here, you've got the smaller face with the kind of bigger ears, and the elongated skull shape on the head." "TSOUKALOS:" "The top of this head looks like an elongated cranium, an elongated skull, and it is identical to this" "Egyptian statue that we find all over Egypt." "To see this picture right here and compare it to the Egyptian bust we see right here, it's uncanny... the head shape is identical." "NARRATOR:" "Do Stanley Hall's artifacts show evidence that" "Egyptian culture could have crossed the ocean to influence" "South American culture?" "Or is it possible that both were influenced by another culture... one from beyond our world?" "If so, were the strange writings inscribed on Father Crespi's metal tablets actual messages from an alien world?" "EILEEN HALL:" "My father went as far as saying it was possibly an advanced civilization, but we can't know for certain until this library is found." "VON DANIKEN:" "So this metallic library is still there in" "Ecuador in a subterranean cave." "There are still Indian tribes living there." "They are still protecting the old treasure." "COPPENS:" "So it's going to push the boundaries of academia once this cave system has been found." "And whether it is Inca or extraterrestrial, it doesn't really matter at this moment in time." "Let's get to this cave and see what is in there." "NARRATOR:" "Perhaps Tayos has yet to reveal all of its secrets, but more than 700 miles to the north, there is another cave... one that may prove that the Mayan underworld and the terrifying gods who ruled it were not only very real, but" "thirsty for human blood." "NARRATOR:" "The Yucatán" "Peninsula... one of Mexico's premier tourist destinations." "Besides scenic beaches, the area is covered by thick jungle and pockmarked by massive sinkholes known as cenotes." "The ground beneath the jungle is also honeycombed with caves." "But here, in 2007, Mexican archaeologist Guillermo de Anda found a cave like no other." "Following clues in the records of 17th-century Spanish priests that hinted at the existence of a mysterious underground Mayan temple deep in the jungle, de Anda found a series of caves near the village of" "Tahtzibichen... caves not seen for hundreds of years, and with entrances submerged beneath centuries of floodwater." "GUILLERMO DE ANDA:" "Sometimes we have to dive into these caves." "Sometimes they go very deep." "The average depth of our research is about 140, 150 feet, but we know of caves much deeper than that." "NARRATOR:" "At first, de Anda and his team found carved stone heads and broken pillars with" "1,900-year-old Mayan inscriptions." "DE ANDA:" "We have found columns under the water, and these columns are amazing because some of them are five feet high and at least ten feet wide." "NARRATOR:" "But as de Anda surfaced in the dry areas of the cave, he found what he believed to be the remains of a massive underground temple complex, including a concrete road, a crumbled pyramid and bones." "But why was it here?" "CHILDRESS:" "The Mayans themselves have, uh, very intriguing legends of an underground world called" "Xibalba." "And it's believed now by archaeologists that what they found is what the Mayans thought was the entrance to this legendary underground world that features prominently in the Popol Vuh." "NARRATOR:" "Could this dark and mysterious cave really be the underground world mentioned in the Mayan legends?" "According to the Popol Vuh, the written record of Mayan mythology, the underworld kingdom of Xibalba, meaning" ""the place of fear," was ruled by the cruel Lords of the Dead, who made those who entered their realm pass through a series of torture chambers, involving blood, darkness, cold, knives," "bats and jaguars." "(snarling)" "MARTELL:" "We see here in this one archaeological spot an actual physical representation of what the Mayans felt the soul had to go through." "NARRATOR:" "Might, perhaps, this cave of stalactites, sharp enough to pierce flesh, represent the "room of knives"" "in the Popol Vuh?" "There is also a "room of bats," and a trench that might once have been filled with blood, like the river of blood that Mayan pilgrims had to cross over." "There are places of cold and darkness... and even a room with the bones of jaguars." "MARTELL:" "These caves were littered with large patches of spiders and reptiles and all types of tumultuous things that a human really wouldn't want to be exposed to." "NARRATOR:" "Although some archaeologists claim this unique site was simply modeled after the description of" "Xibalba in the Popol Vuh, De" "Anda insists that items from the cave date back to a time centuries before the Mayan holy book was written." "DE ANDA:" "It's not that there was this document and they, uh, tried to, uh, imitate what the document said." "I think it's all the other way around." "We believe that we have found the particular Xibalba of the central part of the Yucatán." "This is why we do believe it was a real place." "NARRATOR:" "But if Xibalba is real, were the Lords of the" "Dead also real?" "And if so, who or what were they?" "TSOUKALOS:" "According to the" "Chilam Balam book, which is the" "Book of the Jaguar Priests, it says in there, that at that time "The road to the stars descended from the sky, and the" "13 and nine gods came to Earth."" "I'm sorry." ""Road to the stars," "descended from the sky."" "Can it be more clear?" "I don't think so." "Right there we have a direct reference to someone that has arrived from outer space, and we have a written record about this." "NARRATOR:" "Could the "lords of" "Xibalba" and other Mayan gods really have been extraterrestrial travelers?" "If so, why did they display such a thirst for blood and torture?" "WILCOCK:" "I do not believe human sacrifice was originally taught by the ETs." "I believe it came in the aftermath of when the original teachers of humankind had arrived." "The ancient gods, which were really just humans from another world, withdrew from the area, and the people became distraught." "The more they became distraught, the more they took the original mythology and interpreted it in a much more literal way." "So what might have started out as the myth about the Sun dying and being reborn when it sinks below the horizon, becomes literally the idea of killing people to make sure that the" "Sun is gonna come back up." "NARRATOR:" "As archaeologists and explorers continue to uncover sites where legend and reality meet, could there be even more evidence that mankind's history on this planet is much more profound than what we currently understand?" "There are those who believe the secret lies even deeper within the Earth... as deep as its very core." "NARRATOR:" "The North Pole... a seemingly endless wasteland of" "Arctic ice, shrouded in darkness for six months of every year." "Here, there is no food, no shelter, not even a cave to hide from the slashing winds and temperatures that can dive to 90 degrees below zero." "But according to mainstream geology, beneath the Pole and the Arctic Ocean lies the" "Earth's mostly rocky crust, up to 30 miles thick." "Below this is molten rock, heated by the planet's spinning core, with a solid center of iron and nickel the size of the" "Moon." "Scientists have deduced this information from measurements of Earth's gravity, magnetism and seismic waves." "But no one has ever seen these areas." "Could the frozen surface of the" "Pole be hiding a gateway to a world within our surface world?" "There are those who believe the answer is, "yes."" "And what they believe is known as the hollow Earth theory." "RODNEY CLUFF:" "The hollow" "Earth theory is that, this Earth is not molten inside." "It is actually hollow, and that suspended in the hollow of the" "Earth is an inner sun." "NARRATOR:" "Surprisingly, the notion of a hollow Earth was first given scientific credence by one of the founders of modern astronomy." "DAVID STANDISH:" "The idea that the Earth might be hollow, as a scientific notion, dates back to the astronomer Edmund Halley who is best known for his comet." "In 1691 he presented to the" "London Royal Society his hypothesis that the Earth is hollow and contains several little spheres inside." "Sort of like those Russian" "Matryoshska dolls." "He was hypothesizing this for a very practical reason." "The Earth's magnetic pole moved a little bit every year to the west, and his idea was that our outer sphere had inner spheres that turned independently of the outer one." "He also suggested that these interior spheres would also be able to support life." "NARRATOR:" "In 1818, former" "U.S. Army Captain John Cleves" "Symmes, Jr., announced that there were vast openings at each pole where we could enter" "Inner Earth." "STANDISH:" "With Symmes, the idea of a hollow Earth gets tied into exploring for the pole." "At this point, nobody had actually seen Antarctica, for instance." "NARRATOR:" "The hollow Earth theory again captured the public's imagination in 1864 with the release of Jules" "Verne's second novel, A Journey to the Center of the Earth." "STANDISH:" "The novel takes an" "Icelandic guide and a professor and a young man down into the center of the Earth." "Journey to the Center of the" "Earth could really have been called A Journey to the Center of Geology." "Geology and Paleontology were a very hot topic in the early" "1860s and there's a lot of discussion of that in Journey to the Center of the Earth." "NARRATOR But while Verne popularized the idea that extinct life forms might still exist inside the Earth, others envisioned that the Earth contained advanced underground civilizations." "CHILDRESS:" "Supposedly, they have advanced technology." "They've got ray guns and special weapons." "And even they have flying saucers, other craft like that." "NARRATOR:" "But is there any evidence that such fantastic claims could be true?" "And has anyone actually been to the world within our Earth?" "Proponents of the hollow Earth theory say, "yes," and that one of the explorers was no less a luminary than famed polar pioneer Admiral Richard E." "Byrd." "In the 1920s, Byrd made world headlines by flying over the" "North Pole, and by becoming the first man to fly solo over the" "South Pole." "But hollow Earth theorists believe that the famous explorer went even farther, and that, on February 19, 1947," "Admiral Byrd piloted a plane through a hole near the North" "Pole into the interior of the" "Earth." "CLUFF:" "A flying saucer type craft took control of his airplane, with some kind of tractor beam... and they landed him near an Inner Earth city." "And the message that they had for us was that they consider themselves the guardians of this planet, okay?" "He says, "We don't approve of you people using nuclear weapons."" "We had just blown up a couple of cities in Japan a couple of years before, so this was the message that he was given." "But when he got to Washington, they put a lid of secrecy on this, that this was not to go out." "NARRATOR:" "Some say Admiral" "Byrd's own account of this flight into the hollow Earth is detailed in his secret diary, published in the 1990s, almost four decades after his death." "But skeptics claim the diary is a forgery and point out that in" "February 1947, at the time" "Admiral Byrd was supposedly visiting this other world underneath the North Pole, he was actually part of a vast" "4,700-man Naval exploration called "Operation High Jump,"" "12,000 miles away, near the" "South Pole." "But could Byrd's inclusion in this large military operation at the South Pole have been merely a cover story?" "Some people claim it was, and this allowed him to slip away to the other end of the planet, unnoticed by the media." "GEORGE NOORY:" "Admiral" "Byrd, the rumor was, found a world of flying machines, and people, and... more advanced than us... and that they helped him, and then he left again." "It's a myth." "Nobody's really been able to prove it, but it's a great myth." "NARRATOR:" "Could there really be vast, open spaces within the" "Earth where advanced civilizations live?" "Could extraterrestrial gods really have come here, centuries ago, and hidden the evidence of their journeys deep within caves and tunnels?" "Perhaps we have only just scratched the surface of our planet's underground mysteries." "If so, what clues to our distant past might still be waiting to be found, and hiding in the darkness?" "Captioning sponsored by" "AE TELEVISION NETWORKS"