Seven wonders of ancient Egypt are home to mysteries still unsolved thousands of years after their construction, and today, investigators use cutting-edge tech and forensic analysis to reveal new secrets of these colossal engineering marvels.

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.

Experts explore Hadrian's Villa, the largest Roman palace ever constructed.

Nearly a decade after the ancient site of Nimrud was destroyed by terrorists, experts return to salvage the wreckage; archaeologists piece together the remaining ruins to reveal the origins and brutal decline of a lost empire.

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 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.

Seven American engineering marvels are among the modern wonders of United States, and now, investigators use hidden records to decode and reveal the mysteries behind these historic American icons.

America before Columbus was home to some of the greatest engineering marvels on the planet; special access to hi-tech archaeological digs reveals the secrets of ancient America's Seven Wonders as experts investigate their mysterious purposes.

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.

Cutting-edge archaeological methods help experts unearth the dark secrets hidden at seven wonders of ancient Rome; what they find challenges everything we know about this once-mighty empire.

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

The Red Pyramid at Dahshur is a revolutionary megastructure and the first true pyramid ever constructed in ancient Egypt; experts investigate to reveal the pharaoh who built it and the mystery behind its trailblazing design.

Archaeologists explore Abusir and the secrets of Egypt's Sun Cult pharaohs.

Egypt's ultimate secrets could be hidden underwater, and a cutting-edge archaeological investigation uses hi-tech methods to scan the ocean floor in search of sunken sphinxes, temples, and shipwrecks.

Experts investigate myths of a secret portal to hell in Hierapolis.

Experts investigate an ancient temple monument on an Egyptian island.

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

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.

Experts explore the origins of kings in the lost city of Kish, Iraq.

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.

Experts travel inside ancient mounds to investigate the legend of Midas.

The Tower of London is a centuries-old castle shrouded in a grisly past.

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.