A colossal stone temple on Philae, a remote Egyptian island in the Nile River, mysteriously bears the names of the most famous leaders of the ancient world; now, experts use cutting-edge tech to investigate why pharaohs and emperors all built monuments at this enigmatic site.

The clifftop ruins of Tintagel Castle in Cornwall, England are shrouded in a tumultuous history and believed to be the birthplace of King Arthur; experts use cutting-edge tech to unlock the secrets of this ancient structure and reveal the truth behind a legendary ruler.