The Seven Wonders are the engineering marvels built by great minds of long-lost civilizations, but we're not sure if some even existed. New discoveries & cutting-edge archaeological methods might prove what they looked like and why they disappeared.

The Avenue of the Sphinxes has now been unearthed in the biggest excavation in Egyptian history; using cutting-edge CGI, investigators reveal the hidden secrets of the sphinxes.

The magnificent tomb of Alexander the Great mysteriously vanishes and becomes a legend; using CGI, investigators piece together the evidence to reveal where his tomb lies and what it might look like.

The coliseums of Rome were brutal theaters of spectacle and death that helped control the sprawling Roman empire; now, archaeologists uncover the engineering secrets behind these majestic structures to reveal the truth behind the ancient Roman world.

The Dendera Temple is one of the best-preserved temples in all of Egypt; experts decipher its mystifying zodiac images and uncover the ceremonial events that took place at this sacred site, and stunning CGI rebuilds this grand complex in its prime.

Experts reveal the secrets of the Persian Empire's capital, Persepolis.

When Pompeii was destroyed by an apocalyptic volcano in 79 AD, another Roman town was destroyed, too; experts use cutting-edge tech to investigate the secrets of Vesuvius's second victim, which is one of the most perfectly preserved Roman towns on earth.

The Leaning Tower of Pisa is one of the world's most iconic buildings, and it's also the site of an 800-year-old mystery; using cutting-edge tech, experts investigate the archaeological evidence to reveal when it might finally fall over.

A strange site called Saqqara is home to Egypt's very first pyramid. Here, experts use cutting-edge tech to reveal why the ancient Egyptians started building pyramids and if the mummified animals found here are evidence of a bizarre religious cult.

Experts investigate an ancient temple monument on an Egyptian island.

We reveal the centuries-old secrets and mysteries of one of the most remarkable examples of Victorian engineering. Follow the cutting-edge technology that built the Palace of Westminster, and find how it paved the way for the today's skyscrapers.

The Roman Empire built Hadrian's Wall to guard its frontiers at the edge of the world; new discoveries reveal who the Romans were trying to keep out with this 72-mile-long megastructure and what it tells us about the ancient people of Iron Age Britain.

Pyramids in the deserts of Sudan are the ruins of a powerful lost civilization that rivaled the pharaohs of ancient Egypt. Using cutting-edge tech and archaeological methods, experts are revealing the secrets behind the mysterious Kingdom of Kush.

Palmyra: pearl of the Syrian desert; experts return to the site and use CGI reconstruction to reveal the secrets of Palmyra's ancient engineers.

The Empire State Building is one of the wonders of the modern world, and cutting-edge tech helps experts explore it like never before, revealing the secrets of its construction and the mysteries hidden deep in its foundation.

New discoveries reveal the scandals and secrets of Nero and his lost palace, and using cutting-edge technology, experts might confirm if the infamous emperor burned down Rome so he could build this golden wonder.

New discoveries might lead investigators to the legendary group of 300 Spartan warriors who died fighting off one million invading Persians, and using cutting-edge tech, experts reconstruct the battlefield to uncover the secrets of their last stand.

The Great Wall of China is the biggest man-made structure on the planet -- and one of its biggest mysteries. Follow the scientific mission to reveal the ancient secrets of one of history's greatest empires.

The lost city of Baiae was the Las Vegas of the ancient world -- until a mysterious calamity caused it to sink into the sea. New discoveries reveal the secrets of this sin city that, like Pompeii, some experts believe was destroyed by a supervolcano.

There's a lost city buried in the Sahara. Evidence reveals it's home to Nefertiti, Tutankhamun, and the forbidden god of an outlawed religion; experts use cutting-edge tech to uncover the secret doomsday that caused this strange place to disappear.

The Tower of Babel is one of the most famous stories of the Bible, and to find out if it really existed, archaeologists use cutting-edge tech and the latest science to investigate how ancient engineers could have built such an extraordinary megastructure.

Alcatraz is home to secrets that only cutting-edge archaeology can reveal, and using the latest science and the newest tech, experts search for hidden evidence to investigate why so many tried and failed to escape America's toughest jail.

Experts reveal the mystery behind the decapitated statues of Mount Nemrut.

Experts use cutting-edge tech to unlock the secrets of Tintagel Castle.

The ancient city of Samarra contains a series of medieval structures that hold secrets to one of the world's greatest empires; now, archaeologists use pioneering technology to investigate its astonishing rise to power and reveal its monumental downfall.