Most compelling evidence for the creature known as Bigfoot may be the increasing close encounters that are frightening witnesses in America. Stories have told of interactions range from objects being thrown to frightening abductions by hairy beasts.

In a manoeuvre of strategic brilliance, Moses leads his people out of Egypt and lures the Egyptian army to a watery grave.

Mother Nature unleashes a swarm of tornados on a group of storm chasers. A delivery driver in Japan gets swallowed by the deadliest tsunami in Japan's history. And finally, a massive avalanche barrels into a small town in Norway.

Ruins in Peru support legends of a sunken UFO base and Indian texts talk of water worlds populated by humans and aliens. Could aquatic cities prove that aliens visited?

Gravity is the most powerful and exacting force in the universe. It is pervasive and penetrating. Gravity binds us together, its reach hangs stars in the sky and its grip crushes light.

Could a popular virtual smartphone game actually be part of a CIA surveillance conspiracy? Plus, a look at the terrifying future of weaponised micro-drones, and tracking down the original NSA whistleblower who inspired Edward Snowden.

He was the Norse protector god who battled ogres and a giant serpent. But do historians believe he existed? New discoveries finally unlock the truth behind Thor, god of thunder.

From hidden tunnels beneath Boston to the incredible waterworld under Philadelphia, the Freemasons left behind the blueprints to America's rise.

Most compelling evidence for the creature known as Bigfoot may be the increasing close encounters that are frightening witnesses in America. Stories have told of interactions range from objects being thrown to frightening abductions by hairy beasts.

In a manoeuvre of strategic brilliance, Moses leads his people out of Egypt and lures the Egyptian army to a watery grave.

Mother Nature unleashes a swarm of tornados on a group of storm chasers. A delivery driver in Japan gets swallowed by the deadliest tsunami in Japan's history. And finally, a massive avalanche barrels into a small town in Norway.

Ruins in Peru support legends of a sunken UFO base and Indian texts talk of water worlds populated by humans and aliens. Could aquatic cities prove that aliens visited?

Gravity is the most powerful and exacting force in the universe. It is pervasive and penetrating. Gravity binds us together, its reach hangs stars in the sky and its grip crushes light.

Could a popular virtual smartphone game actually be part of a CIA surveillance conspiracy? Plus, a look at the terrifying future of weaponised micro-drones, and tracking down the original NSA whistleblower who inspired Edward Snowden.

He was the Norse protector god who battled ogres and a giant serpent. But do historians believe he existed? New discoveries finally unlock the truth behind Thor, god of thunder.

Host Eric Geller travels through the dark and damp recesses of Berlin's secret bunkers. Engineered by the Nazis during WWII, their dark past is revealed.

Beneath the waters of north western Canada a fifty foot monster is said to lurk. Stories from Canada's Lake Okanagan date back to the First Nation peoples, who lived in fear of this terrifying creature of the lake that became known as 'Ogopogo'.

The great general leads his huge empire to India. Facing a challenging campaign in tough conditions, Alexander's plan requires tactical brilliance.

Mother Nature attacks Gulf Coast residents with the worst hurricane in US history; a tornado rips through a hardware store, turning merchandise into lethal weapons; and in Haiti, a monstrous earthquake claims countless victims.

'Ancient astronaut' theorists believe aliens have been visiting earth for thousands of years. If so, might we find evidence of this in the stories of America's Old West?

One of the most mysterious ancient civilisations, at its peak the Persian Empire stretched from Greece to India. Why didn't it last?

In a world devoid of people, pythons begin to challenge alligators for control of the Everglades. Elsewhere, Shanghai sinks under the weight of its empty skyscrapers.

Mother Nature continues to wreak havoc: Apocalyptic dust storms suffocate cities around the globe; a tornado chases a family, nearly crushing them; and a volcano errupts almost annihilating the population of the Pacific Northwest.

Host Eric Geller travels through the dark and damp recesses of Berlin's secret bunkers. Engineered by the Nazis during WWII, their dark past is revealed.

Beneath the waters of north western Canada a fifty foot monster is said to lurk. Stories from Canada's Lake Okanagan date back to the First Nation peoples, who lived in fear of this terrifying creature of the lake that became known as 'Ogopogo'.

The great general leads his huge empire to India. Facing a challenging campaign in tough conditions, Alexander's plan requires tactical brilliance.

Mother Nature attacks Gulf Coast residents with the worst hurricane in US history; a tornado rips through a hardware store, turning merchandise into lethal weapons; and in Haiti, a monstrous earthquake claims countless victims.

'Ancient astronaut' theorists believe aliens have been visiting earth for thousands of years. If so, might we find evidence of this in the stories of America's Old West?

One of the most mysterious ancient civilisations, at its peak the Persian Empire stretched from Greece to India. Why didn't it last?

In a world devoid of people, pythons begin to challenge alligators for control of the Everglades. Elsewhere, Shanghai sinks under the weight of its empty skyscrapers.

Mother Nature continues to wreak havoc: Apocalyptic dust storms suffocate cities around the globe; a tornado chases a family, nearly crushing them; and a volcano errupts almost annihilating the population of the Pacific Northwest.

Host Eric Geller travels through the dark and damp recesses of Berlin's secret bunkers. Engineered by the Nazis during WWII, their dark past is revealed.