The Roman Empire built Hadrian's Wall to guard its frontiers; new discoveries reveal who the Romans were trying to keep out with this 72-mile-long megastructure.

The Leaning Tower of Pisa is one of the world's most iconic buildings, but why does it lean? Investigators uncover the reasons for its tilt.

The Tower of Babel is one of the most famous stories of the Bible. Archaeologists use new technology to uncover how engineers could have built it.

What caused the Nazi aircraft to explode into a giant ball of fire over New Jersey in 1937? Experts use cutting-edge technology to investigate the event.

The sunken town of Baiae remains frozen in time, lying on the seabed of the Bay of Naples. Now, marine archaeologists investigate its fascinating secrets.

Thermopylae was the site of an iconic ancient battle. Legend says that in 480BC, 300 Spartan warriors died there - experts reconstruct the lost battlefield.

The 'Iceman' is the world's oldest and most perfectly preserved mummy. Cutting-edge forensic technology may unearth the mummy's darkest secrets.

Troy is the legendary lost city at the centre of the Trojan War, but its existence was never confirmed. New cutting-edge technology explores the ancient myth.

The Nazca Lines are mysterious symbols that have been carved into the Atacama Desert more than a thousand years ago. How and why were they created?

Experts use cutting-edge technology to investigate a lost city buried in the Sahara. Archaeologists are uncovering the city's forgotten ruins and dark secrets.

When Pompeii was destroyed by an apocalyptic volcano, another town was destroyed, too - Herculaneum. It is one of history's most perfectly preserved towns.

The Dead Sea Scrolls in Israel are the oldest biblical texts. New discoveries might finally reveal the hidden meaning behind these manuscripts.

The underground bunker of Adolf Hitler is home to some of the greatest secrets of the Nazi regime. Experts use cutting-edge technology to uncover new evidence.

Alcatraz is one of the most famous prisons in the world. Experts investigate its remarkable engineering secrets and why it was so hard to escape from.

The Lighthouse of Alexandria is one of the world's original Seven Wonders. Experts investigate its many secrets - did it hold a superweapon?

Experts use cutting-edge technology to investigate one of the wonders of the modern world. They reveal mysteries hidden in its foundation.

The Emperor Nero built an astonishing palace in the heart of Rome. Now using cutting-edge technology, experts investigate if he burnt the city for the building.

The infamous gunfight at the O.K. Corral only lasted 30 seconds. Now, experts use cutting-edge technology to uncover the mystery surrounding the event.

Mount Rushmore is one of North America's most iconic landmarks. Experts use cutting-edge technology to reveal what lies beneath the rock.

Cutting-edge technology is helping experts investigate the Bermuda triangle. Using new techniques, they search for evidence of aliens on the ocean floor.

Pyramids in the deserts of Sudan are the ruins of a powerful lost civilisation that rivalled Egypt. However, why are the pyramids there and who built them?

Saqqara is the site of the first pyramid - the Step Pyramid of Djoser. Experts use cutting-edge technology to explore why the Egyptians built pyramids.

Archaeological investigations unearth the secrets of the long-lost city. New evidence reveals what Babylon looked like and what caused its downfall.

The World Trade Centre's iconic twin towers were an engineering marvel.

With special access to a hi-tech archaeological investigation, experts reveal why Egypt's Black Pyramid collapsed before its pharaoh was buried there.