Aliens And Cover-ups: In 1980, a man received a code after touching an alleged spaceship. After the sequence was translated, he was told never to speak of the incident again. (S4, ep 9).

Alien Power Plants: Ancient alien theorists ask whether the Greeks and Egyptians understood electricity. Could extraterrestrials have introduced them to such technology? (S4, ep 10).

Hear from experts and historians as they sit down to untangle the story of the Japanese American soldiers of WWII who fought so valiantly for American democracy.

Explore the refined world of kaiseki ryori, a multi-course meal inspired by the changing seasons where every dish reflects nature's fleeting beauty.

Japan: Travel through time to explore the past 1500 years of one of the world's most unique and diverse ancient cultures - Japan. (S1, ep 10).

Einstein Factor: Ancient astronaut experts believe the minds of Einstein and Galileo were superhuman. Could these historical geniuses have had extraterrestrial connections? (S4, ep 8).

Aliens And Cover-ups: In 1980, a man received a code after touching an alleged spaceship. After the sequence was translated, he was told never to speak of the incident again. (S4, ep 9).

Terror of the Ice Snake: Discover a trail of moving objects in the ice of Antarctica, evidence of one of Joseph Stalin's most insane schemes and a code in the Sonoran Desert. (S6, ep 6).

Strange Bedfellows: The series begins with a look at Germany's allyship with despots and dictators and how these mutual relationships were doomed from the start. (1 of 6).

Wonder(Less) Weapons: Hitler and Goebbels promote wonder weapons as the path to victory as Germany starts to feel overstretched during World War II. (2 of 6).

Home Wrecked Homes: Gas leaks turn suburbs into infernos and high-rise apartments crumble to the earth in an ominous look at the fate that awaits our homes post-apocalypse. (S2, ep 8).

Depths of Destruction: A look at what could happen to the world underground, as minerals grow unchecked in a mine. Back on land, 400 million animals run wild in a town. (S2, ep 9).

The Romans: An awe-inspiring year of archaeological digs with Dr Alice Roberts. Roman finds include an amazing coin hoard and a man buried on a pile of dead animals. (S1, ep 1).

Prehistory: Humans are found to have lived in Britain earlier than thought when tools are unearthed in Norfolk, while some of our ancestors' customs are revealed at another dig. (S1, ep 2).

The British Connection: Ross Kemp starts his journey under Blackfriars Bridge - the location of Britain's first mafia hit - before following the money trail across the UK. (S1, ep 1).

Hell's Agents: Agents Jay Dobyns and Jenna Maguire go undercover to infiltrate the Hells Angels - but the dream of being a fully patched member pushes Jay to the edge. (S1, ep 1).

Motorcycle Murder Club: A Hells Angel proves his loyalty to the gang by leading a mass slaughter of their enemies - but he soon wrestles with his conscience and seeks an exit. (S1, ep 2).

Aliens And Cover-ups: In 1980, a man received a code after touching an alleged spaceship. After the sequence was translated, he was told never to speak of the incident again. (S4, ep 9).

Alien Power Plants: Ancient alien theorists ask whether the Greeks and Egyptians understood electricity. Could extraterrestrials have introduced them to such technology? (S4, ep 10).

The British Connection: Ross Kemp starts his journey under Blackfriars Bridge - the location of Britain's first mafia hit - before following the money trail across the UK. (S1, ep 1).

Hell's Agents: Agents Jay Dobyns and Jenna Maguire go undercover to infiltrate the Hells Angels - but the dream of being a fully patched member pushes Jay to the edge. (S1, ep 1).

Motorcycle Murder Club: A Hells Angel proves his loyalty to the gang by leading a mass slaughter of their enemies - but he soon wrestles with his conscience and seeks an exit. (S1, ep 2).

Thousands of UFO sightings and abductions are reported every year. This series examines these accounts and casts new light on historic cases. (S1, ep 5).

The Da Vinci Conspiracy: Experts scrutinise the paintings, journals and technical drawings of Leonardo Da Vinci. Could they hide evidence of extra-terrestrial beings? (S4, ep 11).

Time Travellers: Scientists explore the possibility that sightings of alien beings or UFOs may be evidence of time travellers from the future. (S4, ep 12).

Aliens And Dinosaurs: Theorists investigate a depiction of a stegosaurus found at Angkor Wat in Cambodia. Could it suggest that alien species killed off the dinosaurs? (S4, ep 13).

Tikal: Discover Tikal, one of the largest and most powerful archaeological sites and urban centers of pre-Columbian Mayan civilisation. (S3, ep 3).

Chichen Itza: Considered one of the New Seven Wonders of the World, the Mayan City of Chichen Itza was the capital of a powerful civilisation. (S3, ep 4).

The Lost Continent (Atlantis): Atlantis, the legendary continent that sank. As the Nazis rose to power, Himmler and the SS were convinced Atlantis existed. Season premiere. (S1, ep 1).

Curse of Genghis Khan: A strange structure discovered in the Gobi Desert could reveal the whereabouts of lost treasure - changing everything we know about Genghis Khan. (S6, ep 7).

The King at Roswell: When a strange plane is discovered near the sight of the Roswell UFO incident, experts wonder if the aircraft has Nazi or extraterrestrial origins. (S6, ep 8).

Treasures of Monster Graveyard: At a mysterious site in the Gobi Desert, experts discover a monster graveyard - a groundbreaking find containing treasures of alien beasts. (S6, ep 9).

The Da Vinci Conspiracy: Experts scrutinise the paintings, journals and technical drawings of Leonardo Da Vinci. Could they hide evidence of extra-terrestrial beings? (S4, ep 11).

Time Travellers: Scientists explore the possibility that sightings of alien beings or UFOs may be evidence of time travellers from the future. (S4, ep 12).

The Anglo Saxons: In Northumbria, skeletons tell tales of violent death and tenderness, and people curate grave goods in an amazing community project. (S1, ep 3).

The Tudors: Dr Alice Roberts pays tribute to the Bard, visiting Shakespeare's first theatre in London's Shoreditch and sifting through the poet's rubbish! (S1, ep 4).

Britannia: A newly discovered town in Devon turns history on its head and there's a shocking find by the Thames - almost 100 baby skeletons. (S2, ep 1).

Aliens And Dinosaurs: Theorists investigate a depiction of a stegosaurus found at Angkor Wat in Cambodia. Could it suggest that alien species killed off the dinosaurs? (S4, ep 13).

US: Ross Kemp heads to New York, discovering the connection between USA and Britain in the rise of the mafia - as well as learning about the infamous Kray twins. (S1, ep 2).

The Killing of Margo Compton: When Hells Angels are linked to the murder of a woman and her daughters, a detective embarks on an 18-year quest to bring the killers to justice. (S1, ep 3).

The Brotherhood Is a Lie: Charles Peewee Goldsmith wanted nothing more than to be a Hells Angel. He fought to become a president, only for the Angels to turn on him. (S1, ep 4).

Time Travellers: Scientists explore the possibility that sightings of alien beings or UFOs may be evidence of time travellers from the future. (S4, ep 12).

Aliens And Dinosaurs: Theorists investigate a depiction of a stegosaurus found at Angkor Wat in Cambodia. Could it suggest that alien species killed off the dinosaurs? (S4, ep 13).

US: Ross Kemp heads to New York, discovering the connection between USA and Britain in the rise of the mafia - as well as learning about the infamous Kray twins. (S1, ep 2).

The Killing of Margo Compton: When Hells Angels are linked to the murder of a woman and her daughters, a detective embarks on an 18-year quest to bring the killers to justice. (S1, ep 3).

The Brotherhood Is a Lie: Charles Peewee Goldsmith wanted nothing more than to be a Hells Angel. He fought to become a president, only for the Angels to turn on him. (S1, ep 4).

Thousands of UFO sightings and abductions are reported every year. This series examines these accounts and casts new light on historic cases. (S1, ep 6).

The New Evidence: Specialists in the field of the extraterrestrial examine new evidence that suggests there was extraterrestrial intervention on Earth in the distant past. (S9, ep 1).

Pyramids of Antarctica: Ancient Astronaut theorists suggest that aliens may have colonised an ice-free Antarctica, before a global event plunged it into the Ice Age. (S9, ep 2).

The Deadly Bermuda Triangle: Explore some of the many theories that could help explain why so many ships, planes and people go missing in the Bermuda Triangle. (S4, ep 11).

A look at the first weeks of a war that would disrupt the lives of so many, starting with the first shots fired by the Japanese in July 1937, China. (S1, ep 1).

The Cave to Hell: Discover images of an Iceland cave that could hold alien secrets, military structures in the Utah desert and a bloody stain in the sands of Saudi Arabia. (S6, ep 5).

The New Evidence: Specialists in the field of the extraterrestrial examine new evidence that suggests there was extraterrestrial intervention on Earth in the distant past. (S9, ep 1).

Pyramids of Antarctica: Ancient Astronaut theorists suggest that aliens may have colonised an ice-free Antarctica, before a global event plunged it into the Ice Age. (S9, ep 2).

Witches: Can a site on the Lancashire-Yorkshire border shed more light on the Pendle Witch trials of 1612? (S1, ep 1).

The Romans: An awe-inspiring year of archaeological digs with Dr Alice Roberts. Roman finds include an amazing coin hoard and a man buried on a pile of dead animals. (S1, ep 1).

Ramses' Egyptian Empire: Vast statues, towering obelisks and incredible temples formed the legacy left by the greatest Egyptian Emperor. Cutting-edge graphics recreate this golden empire.

A look at the first weeks of a war that would disrupt the lives of so many, starting with the first shots fired by the Japanese in July 1937, China. (S1, ep 1).

Sasquatch Sounds & Undersea Alien: Could mysterious lights under the surface of Earth's deepest lake be connected to extraterrestrial life? Tony Harris and his team investigate. (S2, ep 10).

Alaskan Sea Monster & Mystery Jungle Jet: Tony and his team explore time travelers, superhumans and a possible discovery of the lost Malaysian Airlines Flight 370. (S2, ep 11).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 10).

Black Triangle: A look at some of the most widely witnessed UFO events ever, including large black triangular objects in the night sky regularly spotted in the 80s and 90s. (3 of 6).

Houdini Hinds: After scaling walls and eluding officers to escape from three separate high security prisons in the 50s, Alfie Hinds earned the nickname 'Houdini'. (S1, ep 4).

Secrets Of The Seven Seals: Revelation is the most terrifying book in the Bible, describing mankind's final days. But who will survive God's wrath? And when will it happen? (S1, ep 10).

The Deadly Bermuda Triangle: Explore some of the many theories that could help explain why so many ships, planes and people go missing in the Bermuda Triangle. (S4, ep 11).

Henry IV: The Usurper: Best known for usurping and murdering his cousin, Henry IV suffered from a mysterious debilitating skin condition during the later years of his reign. (S2, ep 3).

The New Evidence: Specialists in the field of the extraterrestrial examine new evidence that suggests there was extraterrestrial intervention on Earth in the distant past. (S9, ep 1).

Pyramids of Antarctica: Ancient Astronaut theorists suggest that aliens may have colonised an ice-free Antarctica, before a global event plunged it into the Ice Age. (S9, ep 2).

Invaders: Dr Alice Roberts visits excavations in Orkney and York on the hunt for Viking relics. Finds include an amazing collection of silver and gold. (S2, ep 2).

Vikings: Helen Skelton and Alex Langlands venture to Lindisfarne and the Isle of Man to unearth the secrets of Viking burial grounds. (S1, ep 6).

Black Triangle: A look at some of the most widely witnessed UFO events ever, including large black triangular objects in the night sky regularly spotted in the 80s and 90s. (3 of 6).

Sasquatch Sounds & Undersea Alien: Could mysterious lights under the surface of Earth's deepest lake be connected to extraterrestrial life? Tony Harris and his team investigate. (S2, ep 10).

Alaskan Sea Monster & Mystery Jungle Jet: Tony and his team explore time travelers, superhumans and a possible discovery of the lost Malaysian Airlines Flight 370. (S2, ep 11).

The Prototypes: Through history, mankind has credited its existence to otherworldly beings. Could this be true? Can any proof be found in these early beliefs? (S9, ep 3).

Decoding the Cosmic Egg: Ancient Astronaut theorists examine the creation myth of \"The Cosmic Egg\", and look at why the concept is so pervasive throughout the world. (S9, ep 4).

The Hunt for Stolen Nazi Treasure: Delve into the top theories of where the Nazis hid their wealth, much of which was stolen during World War II. (S4, ep 12).

Between September 1940 and November 1941, things intensify as Nazi Germany exert their dominance over Europe. (S1, ep 2).

Terror of the Ice Snake: Discover a trail of moving objects in the ice of Antarctica, evidence of one of Joseph Stalin's most insane schemes and a code in the Sonoran Desert. (S6, ep 6).

The Prototypes: Through history, mankind has credited its existence to otherworldly beings. Could this be true? Can any proof be found in these early beliefs? (S9, ep 3).

Decoding the Cosmic Egg: Ancient Astronaut theorists examine the creation myth of \"The Cosmic Egg\", and look at why the concept is so pervasive throughout the world. (S9, ep 4).

Henry VIII: More clues to Henry VIII's life are unearthed as Helen Skelton and Alex Langlands join a new dig at one of nearly 60 royal residences owned by the monarch. (S1, ep 2).

Prehistory: Humans are found to have lived in Britain earlier than thought when tools are unearthed in Norfolk, while some of our ancestors' customs are revealed at another dig. (S1, ep 2).

Churchill's Secret Bunkers: Cutting-edge technology gives an insider's look at the subterranean city built within Churchill's secret bunkers during the Second World War.

Between September 1940 and November 1941, things intensify as Nazi Germany exert their dominance over Europe. (S1, ep 2).

Bigfoot Revealed: For 54 years, the Patterson-Gimlin bigfoot film has been the best proof the creature exists. Now with AI technology, the figure is clearer than ever. (S2, ep 12).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 11).

UFOs Crash Sites: Alien autopsies and recovered pieces of an extra-terrestrial spacecraft: this is the story of the Roswell incident and the truth behind the UFO. (4 of 6).

Sphinx: The most monumental ancient sculpture in the world, the half-man, half-lion Sphinx arouses the curiosity of the entire planet - but how was such a huge structure built? (S3, ep 5).

Castle of Chambord: Designed on the medieval model of forts with its enclosure and large corner towers, Chambord is France's largest and most iconic castle. (S3, ep 6).

The Hunt for Stolen Nazi Treasure: Delve into the top theories of where the Nazis hid their wealth, much of which was stolen during World War II. (S4, ep 12).

Walking with Witches: In Nazi Germany, questions about witchcraft attracted SS leaders. Himmler, dedicated to an Aryan super race, established a team to research witchcraft. (S1, ep 2).

The Prototypes: Through history, mankind has credited its existence to otherworldly beings. Could this be true? Can any proof be found in these early beliefs? (S9, ep 3).

Decoding the Cosmic Egg: Ancient Astronaut theorists examine the creation myth of \"The Cosmic Egg\", and look at why the concept is so pervasive throughout the world. (S9, ep 4).

Age of Bronze and Iron: Dr Alice Roberts discovers what Britain was like before the Romans as she examines fascinating finds from the Bronze and Iron Ages. (S2, ep 3).

Elizabeth: In 1592, Elizabeth I visited Sudeley Castle where a spectacular garden was created. 500 hundred years later, a team of archaeologists hunt for this lost gem. (S2, ep 1).

UFOs Crash Sites: Alien autopsies and recovered pieces of an extra-terrestrial spacecraft: this is the story of the Roswell incident and the truth behind the UFO. (4 of 6).

Bigfoot Revealed: For 54 years, the Patterson-Gimlin bigfoot film has been the best proof the creature exists. Now with AI technology, the figure is clearer than ever. (S2, ep 12).

Destination Mars: As we look forward to the first astronauts reaching Mars in the next 20 years, is there evidence to suggest human life was first seeded there? (S9, ep 5).

The Visionaries: Ancient Astronaut theorists suggest that aliens have been guiding mankind in secret to bring about huge leaps in technological advancement. (S9, ep 6).

The Search for Noah's Ark: Explore the most notable theories into the possible whereabouts of Noah's Ark, based on ancient accounts. (S4, ep 13).

From December 1941 to May 1942, Singapore falls, the Wannsee Conference is held in Berlin and a single event in the Pacific transforms the war into a total global conflict.

Curse of Genghis Khan: A strange structure discovered in the Gobi Desert could reveal the whereabouts of lost treasure - changing everything we know about Genghis Khan. (S6, ep 7).

Destination Mars: As we look forward to the first astronauts reaching Mars in the next 20 years, is there evidence to suggest human life was first seeded there? (S9, ep 5).

The Visionaries: Ancient Astronaut theorists suggest that aliens have been guiding mankind in secret to bring about huge leaps in technological advancement. (S9, ep 6).

Robin Hood: Helen and Alex head to Sherwood Forest, the home of Robin Hood, to discover if he ever truly existed. (S1, ep 3).

The Anglo Saxons: In Northumbria, skeletons tell tales of violent death and tenderness, and people curate grave goods in an amazing community project. (S1, ep 3).

Jesus' Jerusalem: A journey back to the Jerusalem that Jesus would have visited throughout his life, using research, expert analysis and cutting-edge technology.

From December 1941 to May 1942, Singapore falls, the Wannsee Conference is held in Berlin and a single event in the Pacific transforms the war into a total global conflict.

Destination Mars: As we look forward to the first astronauts reaching Mars in the next 20 years, is there evidence to suggest human life was first seeded there? (S9, ep 5).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 19).

UFO's vs Airlines: Are UFOs a threat to civil aviation? The culture of silence within the aviation industry could speak volumes. (5 of 6).

The French Revolution: With France composed of the Clergy, the Nobility and everyone else, the chance for people to escape a life of squalor can only come on a tide of change. (S1, ep 3).

Game of Queens: During the Renaissance, the king of France shakes up the foundations of Europe and claims the Scottish crown by marrying queen Mary Stuart to his son. (S2, ep 1).

The Search for Noah's Ark: Explore the most notable theories into the possible whereabouts of Noah's Ark, based on ancient accounts. (S4, ep 13).

Berlin: In the waning days of the war in Europe, the Soviets march into Germany. The Nazis take their final stand as they defend the capital of the Third Reich - Berlin. (S1, ep 6).

Destination Mars: As we look forward to the first astronauts reaching Mars in the next 20 years, is there evidence to suggest human life was first seeded there? (S9, ep 5).

The Visionaries: Ancient Astronaut theorists suggest that aliens have been guiding mankind in secret to bring about huge leaps in technological advancement. (S9, ep 6).

Ice and Stone: Alice Roberts learns more about mankind's Stone Age ancestors, and travels to Jersey to meet a team hoping to shed new light on the Neanderthals. (S2, ep 4).

Romans: Silchester is one of the best preserved Roman sites in Britain. Why did Rome's infamous emperor Nero stamp his mark on the town? (S2, ep 2).

Mutant Mummy & Alien Monolith: A small human-like creature makes loud movements in New Jersey, while monoliths pop up all over the world as the team comb through more evidence. (S2, ep 14).

Birdzilla & New Montauk Monster: An unidentified creature washes up on the beach and an object is seen over the skies of inner Mongolia as Tony and team examine more footage. (S2, ep 13).

UFO's vs Airlines: Are UFOs a threat to civil aviation? The culture of silence within the aviation industry could speak volumes. (5 of 6).

The Next Humans: As science turns towards augmenting humanity with technology, theorists suggest that we are merely following the path of our alien creators. (S9, ep 7).

The Wisdom Keepers: Ancient Astronaut theorists look at the Aborigine legend of Dreamtime, and ask if these stories hold the proof that aliens created life on Earth. (S9, ep 8).

Who Is D.B. Cooper?: Delve into the top theories surrounding the case of Dan Cooper, who hijacked a Northwest Orient Airlines flight, before disappearing without a trace. (S4, ep 14).

By Spring 1942, German armies had taken control, the battles of Midway and Stalingrad begin and American's achieve a ground-breaking milestone in the development of atomic weapons.

The King at Roswell: When a strange plane is discovered near the sight of the Roswell UFO incident, experts wonder if the aircraft has Nazi or extraterrestrial origins. (S6, ep 8).

The Next Humans: As science turns towards augmenting humanity with technology, theorists suggest that we are merely following the path of our alien creators. (S9, ep 7).

The Wisdom Keepers: Ancient Astronaut theorists look at the Aborigine legend of Dreamtime, and ask if these stories hold the proof that aliens created life on Earth. (S9, ep 8).

Dead Peasants: A site on the Welsh border containing almost 1,000 skeletons reveals secrets about life during the Black Death. (S1, ep 4).

The Tudors: Dr Alice Roberts pays tribute to the Bard, visiting Shakespeare's first theatre in London's Shoreditch and sifting through the poet's rubbish! (S1, ep 4).

Braveheart's Scotland: A recreation of 13th century Scotland and the battle against the English army famously fought by the inspirational William Wallace - AKA Braveheart.

By Spring 1942, German armies had taken control, the battles of Midway and Stalingrad begin and American's achieve a ground-breaking milestone in the development of atomic weapons.

Wichita UFO & Booming Sea Sound: The team explores a strange silver object in the sky over Kansas, and whether a sound permeating through the ocean is an otherworldly warning. (S2, ep 15).

Yeti Sighting And Italian Ufo: A bipedal figure crossing a snowy field is rumoured to be the fabled yeti. A colour-changing orb in the sky could be a UFO in Italy. (S2, ep 16).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 13).

Shoot 'Em Down: Fighter pilots from the UK to Peru have encountered UFOs. What happens when a UFO gets too close for comfort? (6 of 6).

Crime and Punishment: Explore the extreme punishments commonly used in ancient Egypt by homicidal royalty. (S2, ep 3).

The Keys to Immortality: Explores humanity's quest for immortality through legendary artifacts like the Holy Grail, Fountain of Youth and Philosopher's Stone. (S1, ep 2).

Who Is D.B. Cooper?: Delve into the top theories surrounding the case of Dan Cooper, who hijacked a Northwest Orient Airlines flight, before disappearing without a trace. (S4, ep 14).

An icon of history, Alexander the Great helped crush the Persian Empire, carry Macedonian arms to India and much more. Explore his legacy in this two-part documentary. (1 of 2).

The Next Humans: As science turns towards augmenting humanity with technology, theorists suggest that we are merely following the path of our alien creators. (S9, ep 7).

The Wisdom Keepers: Ancient Astronaut theorists look at the Aborigine legend of Dreamtime, and ask if these stories hold the proof that aliens created life on Earth. (S9, ep 8).

East: Alice Roberts and Matt Williams present more outstanding archaeology. In the east of Britain, sites include Must Farm, Colchester, Oakington, Lyminge and Silchester. (S3, ep 1).

Invincible: For more than 260 years, HMS Invincible lay at the bottom of the Solent. Now, archaeologists are diving beneath the waves to learn more about this game-changing ship. (S2, ep 3).

Shoot 'Em Down: Fighter pilots from the UK to Peru have encountered UFOs. What happens when a UFO gets too close for comfort? (6 of 6).

Wichita UFO & Booming Sea Sound: The team explores a strange silver object in the sky over Kansas, and whether a sound permeating through the ocean is an otherworldly warning. (S2, ep 15).

Yeti Sighting And Italian Ufo: A bipedal figure crossing a snowy field is rumoured to be the fabled yeti. A colour-changing orb in the sky could be a UFO in Italy. (S2, ep 16).

The Mysterious Nine: Could claims of \"The Nine\" - a federation of extraterrestrial beings who monitor and influence mankind - have any credence? Experts believe so. (S9, ep 9).

The Hidden Empire: Ancient Astronaut theorists suggest that China, with its history of technological advancement and isolationism, could have been the home of alien beings. (S9, ep 10).

Unlocking the Secrets of Stonehenge: The mysterious arrangement of stones found in the English countryside remains a mystery as to how - or why - the landmark was built. (S4, ep 15).

1943 begins with the Casablanca Conference. Events unfold in the week of the Soviet victory in Stalingrad, and one of the best-selling songs in history is released. (S1, ep 5).

Treasures of Monster Graveyard: At a mysterious site in the Gobi Desert, experts discover a monster graveyard - a groundbreaking find containing treasures of alien beasts. (S6, ep 9).

The Mysterious Nine: Could claims of \"The Nine\" - a federation of extraterrestrial beings who monitor and influence mankind - have any credence? Experts believe so. (S9, ep 9).

The Hidden Empire: Ancient Astronaut theorists suggest that China, with its history of technological advancement and isolationism, could have been the home of alien beings. (S9, ep 10).

Stonehenge: As Alex Langlands examines the unique properties of the stones of Stonehenge, Helen Skelton visits the nearby village where its builders lived. (S1, ep 5).

Britannia: A newly discovered town in Devon turns history on its head and there's a shocking find by the Thames - almost 100 baby skeletons. (S2, ep 1).

Hitler's Supercity: A chilling recreation of the unsettling version of Germany that Adolf Hitler had wanted to create, complete with monstrous monuments and built on slave labour.

1943 begins with the Casablanca Conference. Events unfold in the week of the Soviet victory in Stalingrad, and one of the best-selling songs in history is released. (S1, ep 5).

The London Serpent and Moon UFOs: Tony and the team investigate a possible serpentine monster in the Thames and a sighting of a bizarre flying object crossing the moon. (S2, ep 24).

Nessie's Cousin And NYC UFOs: Did boaters really capture footage of a real-life cousin to Nessie. Are glowing orbs floating above NYC cause for concern? Tony and team explore. (S2, ep 18).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 14).

New. A look at decades of reports of mysterious objects, creatures and enigmatic beings seemingly not of this Earth.

Paranormal Mysteries: A woman is terrorised by an invisible attacker and a mother undergoes a violent and demonic transformation. (S2, ep 7).

Unlocking the Secrets of Stonehenge: The mysterious arrangement of stones found in the English countryside remains a mystery as to how - or why - the landmark was built. (S4, ep 15).

Satan Comes to Salem: An inexplicable evil torments the young girls of Reverend Samuel Parris' household before spreading through Salem. The afflicted make witchcraft accusations. (1 of 4).

The Mysterious Nine: Could claims of \"The Nine\" - a federation of extraterrestrial beings who monitor and influence mankind - have any credence? Experts believe so. (S9, ep 9).

The Hidden Empire: Ancient Astronaut theorists suggest that China, with its history of technological advancement and isolationism, could have been the home of alien beings. (S9, ep 10).

West: Alice Roberts and Matt Williams visit the Dorset Country Museum, where they explore finds from archaeological digs across the west of Britain. (S3, ep 2).

Game of Thrones: Archaeologists conduct a dig at Auckland Castle in Co Durham, which 700 years ago was home to a group of power-crazed bishops. (S2, ep 4).

New. A look at decades of reports of mysterious objects, creatures and enigmatic beings seemingly not of this Earth.

Mystery Of Puma Punku: No one knows who designed and built Bolivia's sophisticated temple complex. Could it have been aliens? Experts investigate. (S4, ep 14).

Destination Orion: Experts question ancient civilisations' fixation with the Orion constellation. Could this star group have been an entry point for aliens visiting Earth? (S4, ep 15).

Secrets Of The Tombs: Experts question the startling similarities in burial tombs from distant cultures, asking if aliens could have influenced their complicated designs. (S5, ep 1).

Cold War Warriors: Exploring the Cold War vessels that played pivotal roles in events such as the blockade of Cuba and the Vietnam war. (S1, ep 6).

Secrets And Lies: Learn how Lawrence of Arabia used guerilla warfare against the Ottoman Empire's railways. Also, what secrets lie under New York's Grand Central Station? (S1, ep 6).

Nuclear Near Miss: Machines that would have been used had a stand-off resulted in all-out nuclear war, from the smallest tactical nuke to an experimental flying jeep. (S1, ep 6).

Mystery Of Puma Punku: No one knows who designed and built Bolivia's sophisticated temple complex. Could it have been aliens? Experts investigate. (S4, ep 14).

Destination Orion: Experts question ancient civilisations' fixation with the Orion constellation. Could this star group have been an entry point for aliens visiting Earth? (S4, ep 15).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 11).

The Enemy Within: The Nazis' decision to take on a second ideological war in their racist quest to realise the Aryan ideal leads to the death of millions. (3 of 6).

Drugs, Delusion and Demise: An examination of Hitler's almost daily injection of opioids and methamphetamines and their impact on his murderous regime and his character. (4 of 6).

Take Me To Your Leader: The White House meets its fate in a world without people, and the President's dog must learn the way of the wild. (S2, ep 10).

Secrets Of The Tombs: Experts question the startling similarities in burial tombs from distant cultures, asking if aliens could have influenced their complicated designs. (S5, ep 1).

Invaders: Dr Alice Roberts visits excavations in Orkney and York on the hunt for Viking relics. Finds include an amazing collection of silver and gold. (S2, ep 2).

Age of Bronze and Iron: Dr Alice Roberts discovers what Britain was like before the Romans as she examines fascinating finds from the Bronze and Iron Ages. (S2, ep 3).

Colombia: Ross sees just how prevalent cocaine is in Colombia as he joins an army raid, before meeting the son of Gilberto Rodriguez - a founder of the Cali Cartel. (S1, ep 3).

Leader of the Pack: Former presidents of the Hells Angels give their insights on infamous leader, Sonny Barger, while his ex-wife reveals what destroyed their relationship. (S1, ep 5).

Midwest Meth Madness: Pat Matter is a methamphetamine dealer, but he rises through the ranks to become president of the Minnesota Hells Angels. (S1, ep 6).

Destination Orion: Experts question ancient civilisations' fixation with the Orion constellation. Could this star group have been an entry point for aliens visiting Earth? (S4, ep 15).

Secrets Of The Tombs: Experts question the startling similarities in burial tombs from distant cultures, asking if aliens could have influenced their complicated designs. (S5, ep 1).

Colombia: Ross sees just how prevalent cocaine is in Colombia as he joins an army raid, before meeting the son of Gilberto Rodriguez - a founder of the Cali Cartel. (S1, ep 3).

Leader of the Pack: Former presidents of the Hells Angels give their insights on infamous leader, Sonny Barger, while his ex-wife reveals what destroyed their relationship. (S1, ep 5).

Midwest Meth Madness: Pat Matter is a methamphetamine dealer, but he rises through the ranks to become president of the Minnesota Hells Angels. (S1, ep 6).

Thousands of UFO sightings and abductions are reported every year. This series examines these accounts and casts new light on historic cases. (S1, ep 7).

Prophets & Prophecies: Did prophets such as Elijah and Joseph Smith communicate with a heavenly source or did they actually come into contact with extraterrestrials? (S5, ep 2).

Beyond Nazca: Ancient alien theorists explore the mysterious phenomena of the Nazca Lines. Could these huge geoglyphs in Southern Peru have an extraterrestrial connection? (S5, ep 3).

Strange Abductions: Experts scrutinise The Bible for evidence of alien abductions. Could extraterrestrials have been kidnapping humans for thousands of years? (S5, ep 4).

Sphinx: The most monumental ancient sculpture in the world, the half-man, half-lion Sphinx arouses the curiosity of the entire planet - but how was such a huge structure built? (S3, ep 5).

Castle of Chambord: Designed on the medieval model of forts with its enclosure and large corner towers, Chambord is France's largest and most iconic castle. (S3, ep 6).

Walking with Witches: In Nazi Germany, questions about witchcraft attracted SS leaders. Himmler, dedicated to an Aryan super race, established a team to research witchcraft. (S1, ep 2).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 19).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 13).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 14).

Prophets & Prophecies: Did prophets such as Elijah and Joseph Smith communicate with a heavenly source or did they actually come into contact with extraterrestrials? (S5, ep 2).

Beyond Nazca: Ancient alien theorists explore the mysterious phenomena of the Nazca Lines. Could these huge geoglyphs in Southern Peru have an extraterrestrial connection? (S5, ep 3).

Ice and Stone: Alice Roberts learns more about mankind's Stone Age ancestors, and travels to Jersey to meet a team hoping to shed new light on the Neanderthals. (S2, ep 4).

East: Alice Roberts and Matt Williams present more outstanding archaeology. In the east of Britain, sites include Must Farm, Colchester, Oakington, Lyminge and Silchester. (S3, ep 1).

West: Alice Roberts and Matt Williams visit the Dorset Country Museum, where they explore finds from archaeological digs across the west of Britain. (S3, ep 2).

Beyond Nazca: Ancient alien theorists explore the mysterious phenomena of the Nazca Lines. Could these huge geoglyphs in Southern Peru have an extraterrestrial connection? (S5, ep 3).

The Costa Del Crime: When a century-old extradition treaty between Britain and Spain ended in 1978, the Spanish Coast became a safe haven for the mafia and criminal masterminds. (S1, ep 4).

The Head of the Snake: Posing as a drug dealer, undercover informant Tony Tait infiltrates the secret biker club to take down leader Sonny Barger and meth cook Kenny Owens. (S1, ep 7).

Prophets & Prophecies: Did prophets such as Elijah and Joseph Smith communicate with a heavenly source or did they actually come into contact with extraterrestrials? (S5, ep 2).

Beyond Nazca: Ancient alien theorists explore the mysterious phenomena of the Nazca Lines. Could these huge geoglyphs in Southern Peru have an extraterrestrial connection? (S5, ep 3).

Strange Abductions: Experts scrutinise The Bible for evidence of alien abductions. Could extraterrestrials have been kidnapping humans for thousands of years? (S5, ep 4).

The Costa Del Crime: When a century-old extradition treaty between Britain and Spain ended in 1978, the Spanish Coast became a safe haven for the mafia and criminal masterminds. (S1, ep 4).

The Head of the Snake: Posing as a drug dealer, undercover informant Tony Tait infiltrates the secret biker club to take down leader Sonny Barger and meth cook Kenny Owens. (S1, ep 7).

Game of Thrones: Archaeologists conduct a dig at Auckland Castle in Co Durham, which 700 years ago was home to a group of power-crazed bishops. (S2, ep 4).

Thousands of UFO sightings and abductions are reported every year. This series examines these accounts and casts new light on historic cases. (S1, ep 8).

Space Station Moon: It was mankind's finest hour, the greatest technological achievement of the 20th century - the Apollo 11 mission to the Moon. (S9, ep 11).

Russia's Secret Files: Russia spans over six million square miles of some of the most rugged terrain on Earth, much of which is uninhabited and largely unexplored. (S9, ep 12).

The Legend of Bigfoot: There have been thousands of alleged sightings of Bigfoot across the US, but despite growing evidence, the creature has never been officially identified. (S4, ep 16).

Halfway through its fourth full year, the fortunes of war were running increasingly in favour of the Allies. The bombing of Hamburg and the Allied Tehran Conference take place. (S1, ep 6).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 10).

Space Station Moon: It was mankind's finest hour, the greatest technological achievement of the 20th century - the Apollo 11 mission to the Moon. (S9, ep 11).

Russia's Secret Files: Russia spans over six million square miles of some of the most rugged terrain on Earth, much of which is uninhabited and largely unexplored. (S9, ep 12).

Vikings: Helen Skelton and Alex Langlands venture to Lindisfarne and the Isle of Man to unearth the secrets of Viking burial grounds. (S1, ep 6).

Invaders: Dr Alice Roberts visits excavations in Orkney and York on the hunt for Viking relics. Finds include an amazing collection of silver and gold. (S2, ep 2).

Ancient Supercity: In the 5th century BC, Pericles paved the way for western civilisation when he raided defence funds to build Athens. Experts re-create this first major city.

Halfway through its fourth full year, the fortunes of war were running increasingly in favour of the Allies. The bombing of Hamburg and the Allied Tehran Conference take place. (S1, ep 6).

Bigfoot's Death Cry And Bird On Mars: Experts investigate the theory that Bigfoot makes sounds that can make people sick, and examine images captured by NASA on Mars. (S2, ep 19).

Mysterious Sky Moans And Dragon Sighting: Could a UFO seen by multiple residents of a Florida town be the real deal? Also, a ghoulish moaning sound comes from the sky. (S2, ep 20).

Satellites orbiting our planet have put more eyes on Earth's vast, unexplored areas of land and sea - revealing baffling new anomalies. (S6, ep 15).

Beyond Nazca: Giorgio Tsoukalos draws on evidence from past series as he takes an in-depth look at the mystery of Southern Peru's Nasca Lines. (S1, ep 1).

Festive Fugitives: Six inmates smash a rusted toilet through a bathroom wall in six minutes in order to escape on a Christmas night in Tennessee. (S1, ep 5).

The British Connection: Ross Kemp starts his journey under Blackfriars Bridge - the location of Britain's first mafia hit - before following the money trail across the UK. (S1, ep 1).

The Legend of Bigfoot: There have been thousands of alleged sightings of Bigfoot across the US, but despite growing evidence, the creature has never been officially identified. (S4, ep 16).