The History Channel

What is the meaning behind secret messages found throughout Washington, D.C.? Did America's Founding Fathers know something about ancient aliens that the general public did not? And if so, could this knowledge have been incorporated into the symbols, architecture, and even the founding documents of the United States of America?

There are numerous historical, religious and mythic accounts of ancient civilizations being wiped out by volcanoes, earthquakes, floods, and meteors. Did god, or nature bring about such disasters? Or is it possible that celestial beings had a hand in the ancient world's catastrophic disasters?

Throughout the world, ancient rites and rituals are believed to connect humans to another dimension. But just who--or what--are we communicating with? Could today's rituals, such as festivals, coronations and funerals, be based on early man's attempts to emulate ancient alien visitors? If so, what other ancient rituals might find their roots in a kingdom--not of this world?

Is it possible that sightings of alien beings or UFOs may actually be evidence of time travelers from the future? And might ancient astronauts actually be time travelers from our future? Scientists explore the theoretical possibility of time travel. How can it be achieved? And what might people from 10,000 years in the future look like?

There is evidence that suggests we experienced 20th century alien contact. In 1942, the Battle of Los Angeles involved the US military and Air Defense allegedly fighting a UFO. WWII Allied Air Force planes were buzzed by balls of light that some think could have been extraterrestrial. And the alleged crash of a flying saucer in Roswell, New Mexico in 1947 propelled the world into the age of UFOs. For decades, some people have been searching for the sounds of extraterrestrial intelligence, while others have been sending messages out into deep space. What would happen if aliens answered... or came calling? What protocols exist to determine who would speak on behalf of mankind, and how might we communicate? What happens if they return? Some believe they already have.

Myths and legends have long been regarded as fantastic stories that describe powerful gods, mutant giants and fearsome monsters. But why do so many different cultures, separated by vast distances, tell the same stories? Is it possible that myths and legends were really eyewitness accounts of ancient astronauts descending to Earth? Ancient texts are filled with stories of gods interacting with humans, offering wisdom, technology, and even impregnating women. Could the demigods of mythology have been the offspring of alien and human unions? If so, could aliens have supplied the Missing Link that accelerated human evolution, advancing our civilization and making us who we are today?

Angkor Wat, Cambodia, is the world's largest ancient religious temple. Within its megalithic ruins, researches have discovered a depiction of a species of dinosaur--a stegosaurus. But how could the ancients have had knowledge of animals that mainstream science says died out millions of years ago? Why are dinosaurs extinct? Did an alien race of beings kill off the dinosaurs to make room for humankind?

Ancient underwater cities can be found around the globe, but could these aquatic worlds be the ruins of unknown civilizations--or even proof of extraterrestrial visitations? The infamous tale of the long lost city of Atlantis may be a preserved memory of an ancient alien metropolis. Beneath Lake Titicaca in Peru, the ruins of recently discovered temples support local legends of an underwater UFO base. Ancient Indian texts, known as Sangams, describe sunken cities where aliens and humans intermingled thousands of years ago. Who could have built the 600-foot stepped stone structure off the coast of Japan--a site that may predate the Egyptian pyramids by thousands of years? Could evidence of ancient alien contact lie buried in Earth's deepest oceans?

For thousands of years, there have been places around the world considered dangerous to humans. Might these locations hold the key to an otherworldly connection? At Australia's Black Mountains, local myths speak of ancient serpent gods and hikers disappearing. Every year hundreds are drawn to a dark forest at the base of Mount Fuji in Japan--to commit suicide. What causes these places to be evil? Could there be evidence that past extraterrestrial activity lead to the negative energy in Earth's evil places?

The Pawn Stars prepare to invade when Rick is offered a memoir written and signed by Dwight D. Eisenhower. Detailing his command during WWII, is Rick willing to pay big bucks for this rare book, or will the negotiation force him to retreat? Then, a shop regular piques Rick s interest with a Remington New Model Army. Considered the second most popular pistol of the Civil War, will Rick make an offer, or has popularity diminished its value? And later, Corey and Chum orbit a set of food bags made for Apollo 11. Are the guys hungry to make a deal, or are the seller s expectations out of this world?

Pop goes the Pawn Stars when four original paintings by Andy Warhol brush by. Do the guys give these rare works 15 minutes of fame, or just send them back to the factory? Then, a baseball signed by members of the infamous 1919 Chicago Black Sox has Rick and Corey seeing green. Will the guys signal for a steal, or does a tough negotiation knock the price out of the park? And later, a pair of 10k gold sunglasses comes in on the night shift. Can Chumlee and Olivia eye a good deal on these vintage specs, or will the seller have it made in the shade?

Burning up the back roads of South Dakota, Mike and Frank get off to a great start in Jim's spectacular man-cave. But when he slams on the brakes, they switch gears to score a heavenly sign. Freestyling in Iowa, the guys take a chance at an old airport turned auto body shop where a retro car takes them back to the future. Packed with roadside relics, Norm's property features a jaw-dropping collection of vintage pedal cars but the guys soon discover he drives a hard bargain.

Informational programming.

Informational programming.

Informational programming.

Informational programming.

Informational programming.

Informational programming.

In March 1862, the North's EM Monitor /EM and the South's EM CSS Virginia /EM clashed in an inclusive battle. But the ironclads changed naval warfare forever, their armor plating dooming wooden warships to the scrap heap.

There is evidence that suggests we experienced 20th century alien contact. In 1942, the Battle of Los Angeles involved the US military and Air Defense allegedly fighting a UFO. WWII Allied Air Force planes were buzzed by balls of light that some think could have been extraterrestrial. And the alleged crash of a flying saucer in Roswell, New Mexico in 1947 propelled the world into the age of UFOs. For decades, some people have been searching for the sounds of extraterrestrial intelligence, while others have been sending messages out into deep space. What would happen if aliens answered... or came calling? What protocols exist to determine who would speak on behalf of mankind, and how might we communicate? What happens if they return? Some believe they already have.

Myths and legends have long been regarded as fantastic stories that describe powerful gods, mutant giants and fearsome monsters. But why do so many different cultures, separated by vast distances, tell the same stories? Is it possible that myths and legends were really eyewitness accounts of ancient astronauts descending to Earth? Ancient texts are filled with stories of gods interacting with humans, offering wisdom, technology, and even impregnating women. Could the demigods of mythology have been the offspring of alien and human unions? If so, could aliens have supplied the Missing Link that accelerated human evolution, advancing our civilization and making us who we are today?

Angkor Wat, Cambodia, is the world's largest ancient religious temple. Within its megalithic ruins, researches have discovered a depiction of a species of dinosaur--a stegosaurus. But how could the ancients have had knowledge of animals that mainstream science says died out millions of years ago? Why are dinosaurs extinct? Did an alien race of beings kill off the dinosaurs to make room for humankind?

Ancient underwater cities can be found around the globe, but could these aquatic worlds be the ruins of unknown civilizations--or even proof of extraterrestrial visitations? The infamous tale of the long lost city of Atlantis may be a preserved memory of an ancient alien metropolis. Beneath Lake Titicaca in Peru, the ruins of recently discovered temples support local legends of an underwater UFO base. Ancient Indian texts, known as Sangams, describe sunken cities where aliens and humans intermingled thousands of years ago. Who could have built the 600-foot stepped stone structure off the coast of Japan--a site that may predate the Egyptian pyramids by thousands of years? Could evidence of ancient alien contact lie buried in Earth's deepest oceans?