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.

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.

Experts investigate bunkers that conceal a deadly nuclear secret.

Experts investigate the deadly legacy of an abandoned sea fort.

A desert island contains a marooned structure with a contagious past.

A war-torn Italian ghost town immortalized by a legendary Hollywood director blurs the lines between fiction and reality; experts investigate and uncover a forgotten landscape of ruins captured in a WWII documentary.

The ruins of a dreamlike Polish palace hide an astonishingly dark history that's shrouded in mystery to this day; experts investigate and uncover an ornate gothic structure that concealed a nightmare of Nazi experimentation.

Experts uncover a derelict resort complex constructed by the Russian mafia.

The haunting remains of an isolated ghost town high in the Colorado mountains suggest a once booming mining community left in devastation; experts uncover an inhospitable land of shattered dreams where fortune seekers chased the American dream.

An enormous concrete box with bizarre circular openings looms on the coast of an island near mainland China; Experts investigate and uncover tunnels leading to an enormous underground complex that nearly triggered a nuclear war.