The world's abandoned structures hold new evidence about the lives and deeds of history's greatest heroes and villains, and using the latest discoveries at these mysterious sites, experts count down the ten most significant.
Long, dome-like structures camouflaged by a rural landscape conceal the remains of concrete vaults with a hidden history; experts investigate and uncover state-of-the-art bunkers built to conceal and protect a deadly nuclear secret.
A desert island adrift in the Gulf of Mexico contains a massive and marooned structure with a contagious past; experts investigate and uncover a desolate military fortress turned prison and plagued by a deadly disease.
A collection of ramshackle structures with a mystical facade lie mysteriously deserted on the tropical island of Bali; experts investigate and uncover the ruins of a bizarre amusement park complex with a disastrous past.
A strange sea fortress that guards icy waters is home to a grim secret; experts investigate the mysteries at this eerie structure, which fought an invisible enemy far more deadly than ever imagined.