Did a biblical patriarch receive instructions from 200 angels high above the earth? Were the ancient Greeks taught how to work metal by a race of fish-people? And might Egypt's most controversial pharoah have been an extraterrestrial being?

Ancient Astronaut Theorist Giorgio Tsoukalos takes a look back at The Top Ten Extraordinary Creatures we've investigated creatures that just might provide compelling evidence of extraterrestrial visitation.

Ancient Aliens is counting down the top ten locations around the world that might be hiding alien bases, including a cavern beneath the ice of Antarctica, a lake in China that is a hotspot for UFOs, and a pyramid under the slopes of Mt. Denali.

Counting down the top 10 scariest encounters that just might be evidence of extraterrestrial visitation.

Counting down 10 intriguing symbols and codes found across the globe that might contain proof of otherworldly contact.

Ancient Aliens is counting down the top ten most devastating disasters ever documented that might have an otherworldly connection.

The ancient Sumerians established what is considered the world's first civilization, and they credited their extraordinary achievements to their gods, the Anunnaki.

For years, Scotland has been an epicentre of otherworldly phenomena. It is home to ancient stone circles, stories of strange beings and a major hotspot for UFO sightings.

Along the Earth's north 37th parallel there have been so many reports of UFO's and other mysterious events that it has been dubbed The UFO Superhighway.

There are mysterious ancient stones shaped into perfect spheres. Many of them show clear evidence of being manmade and some completely defy explanation. Could the mystery of the stone spheres provide clues about humankind's alien past?

Humanoid robots are rapidly reaching a level of sophistication that was thought to exist only in science fiction. But is the obsession with creating counterfeit humans really pointing the way to mankind's future - or to its past?

Is it possible that an advanced civilization inhabited Earth thousands of years ago? Could the stories of a time when gods and otherworldly beings inhabited the planet be more than just mythology?

Did aerospace engineer Wernher von Braun have secrets collected by the Nazis in WWII, or access to technology recovered from Roswell? Is it possible that the world's greatest rocket scientist found his inspiration not on our world, but another?

In nearly every culture there are stories of opposing forces at work here on Earth - forces of a supernatural or otherworldly nature. Could these forces really exist? And if so, what is the true nature of the dark forces?

Ancient astronaut theorists have suggested that many of the divine beings depicted in cultures throughout the world are not really divine - or mythological - but instead reflect extraterrestrial visitations that our ancestors did not understand.

Since the launch of the Kepler Telescope in 2009, scientists have identified thousands of planets capable of supporting life. Is it possible that this discovery could finally answer the age-old question: are we alone in the universe?

In August of 2014, Russian cosmonauts aboard the International Space Station discovered something incredibly unexpected covering parts of the windows - living sea plankton. If sea life can thrive in space, might the reverse be true as well?

Ancient Aliens examines 75 million years of the most credible alien evidence here on Earth, from the age of the dinosaurs to ancient Egypt to the skies over the western desert in present day USA.

Might the United States military really have a secret space programme? And if so, are we preparing for a space-based war with other nations... or other species?

In Iraq and Syria, thousands of ancient artifacts and relics have been deliberately destroyed. In the highlands of Tibet and the jungles of Central America, sacred texts have been systematically destroyed. Could this all be by design?

How can ancient tombs across the world have so many remarkable similarities? Ancient Astronaut theorists believe that some of these tombs were designed with the help of extraterrestrials.

For thousands of years, human civilisation has been guided by the words and deeds of ancient prophets, but who were these prophets communicating with?

The Nazca lines are hundreds of gigantic lines that extend for miles throughout a remote Peruvian desert. Could the massive markings have an alien connection?

Researchers explain how alien encounters are not a modern phenomenon, and ask if there could be an alien agenda behind the abduction of humans.

What compelled ancient man to move colossal stones to build remarkably similar stone monuments all around the world, from the jungles of Costa Rica to England’s countryside?

The gods worshipped by the Norse Vikings were fearsome and mysterious. Experts investigate whether these powerful Viking Gods could have been visitors from another planet.

An examination of Erich von Däniken's controversial theories that have captured the attention of the world and ignited a movement known as Ancient Astronaut Theory.

Ancient emperors, kings and pharaohs were often attributed with otherworldly strengths, abilities and wisdom, and many were even considered gods by the people they ruled. Who were these exceptional leaders?

Accounts from various cultures describe similar divine, birdlike figures that brought advanced medical knowledge to mankind thousands of years ago. Who were these ancient surgeons?

All around the world, archaeologists have uncovered mysterious relics revered by ancient cultures for thousands of years. What is it about these ancient objects that draws people to them?

This episode examines new interpretations of ancient texts, which indicate that Satan may have been an extraterrestrial being, rather than an immortal force of evil.

Could the Anunnaki gods be more than legend? Is it possible that civilization made sudden, huge advances in development 5,000 years ago as a result of their presence on Earth?

Are crystal skulls an elaborate hoax? Or do they possess a great, perhaps even otherworldly power? This episode examines arguably the most controversial of ancient artefacts.

Reverence for the number three dates back thousands of years, and can still be found today in art, architecture, science, literature and religion. What is it about this number that continues to fascinate mankind?

Throughout the ancient world, magic was used for everything from healing to communicating with the gods. But did magic really exist in the ancient times as a means of replicating the power of the gods?

Studies have shown that up to 70% of all UFO sightings happen in so-called 'hotspots' where reports of visions, mysterious lights and unusual phenomena are regularly witnessed.

More than 10,000 crop circle formations have been documented in over 50 countries, and many display properties that defy conventional explanations.

The discovery of the ancient megalithic site of Karahan Tepe in southern Turkey turns the world of archaeology on its head.

The obelisks of ancient Egypt was perfectly carved from a single granite rock.

MUFON is the world's leading organization devoted to the scientific investigation of unidentified aerial phenomena and other unexplained encounters. Could MUFON's extensive database contain definitive proof of extraterrestrial visitation?

Meteor impacts changed the world, creating the ideal environment for human civilisation and providing essential metals. But could new evidence reveal that celestial objects have been directed to Earth by alien intelligence?

The Center for the Study of Extra-Terrestrial Intelligence defines a "Close Encounter of the Fifth Kind" as direct human contact and communication with extraterrestrial life. But will this classification only become useful in the distant future?

Pilots report terrifying UFO encounters, including aircraft control takeover & entire jumbo jets vanishing. Such unexplainable events have occurred since the dawn of aviation, leading to speculations about extraterrestrial presence in the airspace.

Enormous megalithic structures of mysterious origins - could the ancient mysteries that exist on the Mediterranean islands of Malta be connected to local legends of alien visitation and giant hybrid beings?

Counting down the world’s top ten pyramid sites, from a valley in Peru with over 250 hidden pyramids to an ancient Greek city with mysterious 4800-year-old ruins to Egypt’s famous Giza Plateau.

Counting down the world's top ten mysterious devices, from strange, grooved disks found in a cave in China to an ancient Greek computer. Might these sensational artefacts provide evidence of extraterrestrial visitation?

Counting down the world's top ten mysterious islands, including sites said to be home to giants and islands that disappear into thin air.

Counting down the top ten alien craft, from V-shaped objects to orbs of light to flying saucers.

Examining 75 million years of the most credible alien evidence here on Earth, from the age of the dinosaurs to ancient Egypt to the skies over the western desert in the present day.

In the early 1900s, Edgar claimed to receive visions of both the past and the future while in a trance, he healed the sick, and alleged to have encounters with otherworldly beings. Could it be that he was a vessel used to carry out an alien agenda?

Counting down the top ten mysteries of the deep, from sunken continents to ruins on the ocean floor and even artifacts that may be remnants of Atlantis.

More than 3,000 years ago, the ancient Greeks credited their most monumental achievements to gods like Zeus, Apollo, and Poseidon. But is it possible that these powerful beings from Mt. Olympus were, in fact, extraterrestrial visitors to Earth?

In the 21st century, UFOs have gone from fringe science to mainstream obsession. UFO hunters are using incredible technology, and UFOs are being openly investigated. Are we closer than ever to understanding the strange events happening in our skies?

Talismans are seen as providing protection and good fortune. Some are even thought to embody a higher power. Could it be that what fuels our faith in talismans is not superstition, but a real connection to something beyond our world?