Treasure hunters have searched for a lost Incan city of untold wealth for a century, but new technology might finally locate its riches; a strange mountain in Egypt sparks an investigation into Cleopatra's gems and the tomb of Alexander the Great.

A ghost ship is found abandoned on a remote island that's home to one of the world's last uncontacted tribes; a strange labyrinth in Sicily might have a sinister connection to the Mafia; new evidence reveals a mysterious military compound in Russia.