Secrets Of The Underground

Rob Nelson investigates the mysterious rocks at the bottom of Lake Michigan known as Underwater Stonehenge. Plus, the search for escape tunnels in Alcatraz.

Rob Nelson investigates mysterious tunnels under Denver's airport. Plus, in Ohio he tries to uncover the secrets of a giant serpent-shaped mound.

Rob Nelson investigates rumours of secret underground escape route used by infamous gangster Al Capone. Plus, mysterious earthen mounds in Washington State.

Rob Nelson hunts for a mass grave that could expose a dark secret. Plus, a giant lake is mysteriously disappearing and Rob set off to find out why.

Rob examines bizarre markings that suggest a violent clash between prehistoric beasts. In California, he explores if a strange lake is a home to alien life.

Rob heads to California to investigate a network for major fault lines that could set off a mega-quake. Plus, he explores a mysterious sinkhole.

Rob Nelson investigates a cluster of ancient ruins in New England that suggest Europeans arrived in the Americas almost 1,000 years before Columbus.

Rob Nelson heads to Lake Michigan to investigate an unexplained, Bermuda Triangle-like phenomenon that has caused ships to disappear for centuries.