Examine the efforts under way to establish a human colony on Mars, including plans to grow food, recycle waste water and introduce a breathable atmosphere.

Is it possible that sightings of alien beings or UFOs may actually be evidence of time travellers from the future? Scientists explore the theoretical possibility of time travel.

After the fall of Rome, autonomous city states emerged and revitalised their cities with new and radical designs. Explore how a new Italy was built.

Deep in the Egyptian sand, Zahi make the extraordinary discovery of five intact burials and, just as he thinks things couldn't get any better, he unearths a brutally murdered mummy.

At the bottom of an Arctic fjord in Norway, Tim dives on Nazi relics that may blow the case wide open. Mike and James encounter a smuggler who leads them to a Nazi castle on the Italian border.

Cities of the Underworld

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

From greed and gore to Grand Masters, we recreate this covert world of secrets and power.

Examine the efforts under way to establish a human colony on Mars, including plans to grow food, recycle waste water and introduce a breathable atmosphere.

Is it possible that sightings of alien beings or UFOs may actually be evidence of time travellers from the future? Scientists explore the theoretical possibility of time travel.

After the fall of Rome, autonomous city states emerged and revitalised their cities with new and radical designs. Explore how a new Italy was built.

Deep in the Egyptian sand, Zahi make the extraordinary discovery of five intact burials and, just as he thinks things couldn't get any better, he unearths a brutally murdered mummy.

At the bottom of an Arctic fjord in Norway, Tim dives on Nazi relics that may blow the case wide open. Mike and James encounter a smuggler who leads them to a Nazi castle on the Italian border.

Cities of the Underworld

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

From greed and gore to Grand Masters, we recreate this covert world of secrets and power.

Examine the efforts under way to establish a human colony on Mars, including plans to grow food, recycle waste water and introduce a breathable atmosphere.

After the fall of Rome, autonomous city states emerged and revitalised their cities with new and radical designs. Explore how a new Italy was built.

Deep in the Egyptian sand, Zahi make the extraordinary discovery of five intact burials and, just as he thinks things couldn't get any better, he unearths a brutally murdered mummy.

Mike and James excavate the grounds of a remote Alpine hotel in search of buried Nazi dead drops. In Rome, Lenny and Gerrard make a shocking discovery that implicates some of the world's most powerful people.

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.

In 1939, a group of scientists warned FDR that Germany might be developing an atomic bomb. Roosevelt issued an order: America had to make the first weapon. We recreate the world of classified nuclear facilities.

Planetary collisions, meteor impacts which cause mass extinctions, clusters of comets and asteroids: is our universe just one big cosmic shooting gallery?

Experts examine depictions of dinosaurs in the world's largest ancient religious temple. Could an alien race have killed the dinosaurs to make room for humans?

Researcher Marc Seifer recruits astrophysicist Travis Taylor and investigative journalist Jason Stapleton to help unravel the mystery of inventor Nikola Tesla's missing files, which were confiscated by the US government after he died in 1943.

When WW2 breaks out, an elite force of German U-boat commanders attempt to starve Britain into submission. Vera Mathews heads the reformed WRENS. Meanwhile retired naval commander Gilbert Roberts is desperate to return to his career.

The Romans, with the greatest army in the world, are annihilated by Germanic tribes at the Battle of Teutoburg Forest. Go inside the culture of some of the most famous warriors to explore their weaponry, tactics and, ultimately, their psyche.