Rob Nelson investigates rumours of secret underground escape route used by infamous gangster Al Capone. Plus, mysterious earthen mounds in Washington State.
A legendary train filled with stolen Nazi gold is said to be hidden in Poland. Rob and Stefan explore deep under the earth's surface to uncover the truth.
Priceless gold and silver artefacts are believed to be lost in King Solomon's hidden mines. Rob and Stefan search for the legendary treasure.
Nikola Tesla died before he finished a mysterious, earth-shattering invention. But the ground beneath his only remaining lab may hold clues.
Beneath the densely populated city of Naples lies a looming threat. A super volcano may be on the verge of erupting and cause an apocalyptic catastrophe.
New theories claim the sunken city of Atlantis may have been in the Americas. From the Bahamas to an ancient site in Louisiana, Rob and Stefan seek the evidence.
A strange cave freezes in summer and melts in winter, and a huge sand dune swallows a small child in an instant. Rob and Stefan explore these mysteries.
When an infamous pirate city sunk into the sea, a huge treasure may have gone with it. Could cutting edge technology reveal its resting place?
In California Rob and Stefan explore a cave, rumoured to house 100 pounds of gold stashed away during the Gold Rush. Can their tech end the mystery?