History's Greatest Mysteries - Season 3

An infamous Cold War cold case: nine hikers found mutilated on a remote mountain slope. For over 60 years, authorities and amateurs alike have been trying to figure out what happened, in a place that's been called "Russia's Area 51."

As the Cold War ramps up, a well-dressed man is found dead within miles of a nuclear testing site on a tranquil Australian beach. There are no clues to his identity. Who is the Somerton Beach man, and how did he die?

After a series of dark and ominous events, an unassuming family home on Long Island becomes the most notorious house in America. 50 years later, it's spawned a title wave of books, documentaries, and films; but do haunted houses really exist?

It's a treasure coveted by everyone from Roman Emperors to Adolf Hitler--a sacred object said to hold incredible powers of healing, resurrection and immortality. It may be the world's most sought-after relic, but what is the Holy Grail?