The lost city of Olous, a great metropolis along the north coast of Crete, lies submerged in the Mediterranean. Archaeologists uncover its secrets using pioneering technology and CGI reconstruction.

The Avenue of the Sphinxes has been unearthed in modern Luxor (the ancient capital city of Thebes) with the most extensive excavation in Egyptian history. This avenue connects Karnak Temple with Luxor Temple, where sphinxes and ram-headed statues line both sides. The ancient Opet Festival celebrated the annual flooding of the Nile and included a ritual procession following this path. Using cutting-edge CGI, investigators reveal the hidden secrets of the sphinxes.

Located along the Gulf of Corinth, the Greek city of Helike vanished in 373 B.C.; archaeologists believe they've found the ruins of the great lost metropolis. Using CGI, experts re-create the city's final moments and reveal its links to the greatest lost land of all -- Atlantis.

The magnificent tomb of Alexander the Great, the Soma in Alexandria, Egypt, mysteriously vanishes from history 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.

Palmyra: the pearl of the Syrian desert. Why was this glorious city built here? Experts return to the site since it was extensively damaged by the terrorist organization ISIS from 2015 to 2017 and use CGI reconstruction to reveal the secrets of Palmyra's ancient engineers.