Nazca remains one of the most mysterious sites on Earth. The vast desert floor is covered with hundreds of ancient geoglyphs depicting animals, human-like figures and strange geometric designs. But, many of these glyphs are so large they can only be fully viewed from the sky. Perhaps even more intriguing are the strange flat-topped mountains that appear to have had their peaks sliced off, and a band of man-sized holes that stretch for almost two miles across the desert. Could these ancient geoglyphs and mysterious landscapes hold the key to proving Earth was visited by aliens in the distant past? Ancient Astronaut theorist Giorgio Tsoukalos, along with author David Childress, investigates the origins and meanings of the mysterious symbols and shapes found in the desert of Peru.

At the height of World War II, the Nazis engaged their top scientists to develop “wonder weapons”–weapons that were so scientifically advanced they could have turned the tide of the war against the Allies. According to testimony, one of the top-secret projects was code-named “Die Glocke.” Die Glocke was believed to be a bell-shaped time travel device that could soar through the sky and eventually reach the speed of light and beyond. Did Die Glocke actually exist? And if so, could it have been based on alien technology? Theorist Giorgio A. Tsoukalos travels from Poland to Pennsylvania on the trail of the Nazis’ “wonder weapon.” Did the Nazis find advanced knowledge in ancient texts that enabled them to develop anti-gravity technology? And was the construction of a time travel device made possible by reverse-engineering extraterrestrial technology?

The ancient ruins of Puma Punku have mystified archaeologists ever since their discovery hundreds of years ago. The massive stones are precisely carved into blocks that are unlike anything found anywhere else in the world. Is it possible that the ruins of Puma Punku offer evidence of advanced technology being used in the ancient past? And if so, might this technology have been provided by alien beings–beings who ultimately destroyed the site to conceal whatever they built? Ancient Astronaut theorist Giorgio A. Tsoukalos explores the construction and mysterious history of one of the most unique ancient sites on Earth. What was the purpose of the vast building at Puma Punku? Why is there no evidence of the precision tools required to create the unique blocks and sophisticated masonry found there? What could have destroyed this massive structure? Is it possible that Puma Punku is thousands of years older than previously thought?

Ancient Astronaut Theory has existed in popular culture for nearly 50 years, asking the question whether extraterrestrials visited Earth in the remote past. All around the world there are examples of physical evidence that suggest humans are not alone in the universe. But has this evidence been left behind for a purpose? Is it in fact a series of clues, or Alien Code, that we are meant to decipher? Ancient Astronaut theorist Giorgio A. Tsoukalos investigates unexplained mysteries from every corner of the world. The evidence shows that many ancient sites, and even modern ones like Roswell, all seem to be associated with legends and reports of someone or something coming down from the sky. Tsoukalos’ research demonstrates that many of these sites share a common symbol or shape–concentric circles. What is the significance of these designs, and is it possible they contain a coded, mathematical message left by alien visitors in the remote past?

Ever since Plato first wrote about the mysterious island of Atlantis, it has captured the imagination of adventurers and academics alike. Was Atlantis merely a myth, or could it have actually existed in the remote past? Did Atlantis just disappear as Plato described? And could it have been the home of an advanced civilization that created the human race? Ancient Astronaut Theorist Giorgio A. Tsoukalos explores the most recent discoveries related to the centuries old story of Atlantis. By investigating a series of clues, Tsoukalos endeavors to narrow down the possible location of Atlantis. Could evidence be found in a strange egg-shaped stone in Portugal? What secrets can be uncovered on the island of Santorini, Greece? Could Atlantis have been an empire with a network that stretched around the world? Or was it something else entirely? Something that, perhaps, came from the stars?

The Loch Ness Monster is one of the world’s most enduring mysteries. But there have also been accounts of similar cryptids all over the planet. Sightings of these mysterious creatures have been documented for hundreds of years in various cultural folklores. Are these fantastic creatures leftover dinosaurs, mythical animals or something that traveled to Earth millions of years ago? Or might the sightings of these strange beasts be a glimpse into the past caused by a disturbance in the space-time continuum? Ancient Astronaut theorist Giorgio Tsoukalos travels from the Highlands of Scotland to the shores of Vermont’s Lake Champlain in his quest to learn more about these elusive lake monsters. Could there be a link between two of the most famous creatures in the world–Nessie and Champ? Is there a correlation between the geology of their locations? And what surprising role might physics play in understanding just what eyewitnesses claim to have seen?

A mysterious rock bearing a cryptic design was discovered in Roswell, New Mexico in 2004. Now coined “The Roswell Rock,” this piece of stone is unusually smooth and possesses unique magnetic properties. Even more intriguing is that the motif on the rock–a sequence of triangles and crescents–is an exact match to a crop circle found in England nearly two decades ago. Ancient Astronaut Theorist Giorgio Tsoukalos sets out to determine the origin of this intriguing stone. Through a series of experiments Tsoukalos unveils whether The Roswell Rock is merely a man-made fabrication or something much more. How could the precise design have been created without leaving evidence of altering the stone? Why does this small rock react to magnets? And most baffling of all–why does the design match a crop circle that appeared more than 4,000 miles away from the Nevada desert?

The mysterious Mediterranean island of Malta lies south of Sicily and is home to megalithic structures built by a mysterious prehistoric society. According to scholars, the massive blocks even pre-date the Great Pyramid of Giza. Just who were the people that built these sophisticated structures? Local folklore describes Malta as being the home of giants and the legendary one-eyed creature known as Cyclops. Could these stories be true–or could they offer clues to an extraterrestrial connection? Ancient Astronaut theorist Giorgio Tsoukalos investigates Matla’s giant stone structures, unexplained rock carvings and mysterious elongated skulls. Could these strange antiquities be connected–and might they prove that there was a highly advanced civilization on Malta in the remote past–one that was perhaps in contact with ancient astronauts?

The imposing city of Washington D.C. was inspired by the ancient world, as seen in the Greek pillars, Roman domes and even an Egyptian-style obelisk that mark the landscape. But is it possible that the designs and philosophies enshrined in the streets of the U.S. capital were influenced by an otherworldly source? Ancient Astronaut theorist Giorgio A. Tsoukalos travels to Washington D.C. and Philadelphia to investigate the origins of the American democratic experiment. Did George Washington have an alien encounter at Valley Forge–one that gave him mystical protection throughout the American Revolutionary War? Does the way Washington D.C. was planned and constructed hold any clues to the beliefs of the nation’s founding leaders? Did the Native American stories of Sky Gods play a role in the establishment of the United States? Might the inspirational ideas of reason and science embraced by the Founding Fathers have in fact been seeded by an extraterrestrial intervention?

In 1958, a bulldozer operator in Northern California discovered 16-inch human-like footprints, and the legend of Bigfoot was born. Today, there are hundreds of reported sightings of big hairy monsters in America, but nowhere are the stories more prolific than in America’s Pacific Northwest. Many reports of encounters with the giant hair-covered creature are accompanied by accounts of UFO activity and unexplained lights in the sky. Could the creature known as Bigfoot, or Sasquatch, really exist? If so, could it be living proof that extraterrestrials were not only here, but may still be living in our midst? Ancient Astronaut theorist Giorgio A. Tsoukalos joins the Olympic Project and anthropologist Dr. Jeff Meldrum on an overnight expedition on the Olympic Peninsula in Washington. Will their arsenal of high-tech equipment capture images or sounds that confirm Bigfoot’s presence?