Secrets of the Underground

Investigating rumors of a secret underground escape route used by the infamous gangster Al Capone; trying to uncover who or what built a vast landscape of earthen mounds in Washington state.

Exploring mysterious tunnels beneath Denver's airport, capitol building and downtown to investigate rumors of a secret organization that operates below; in Ohio, trying to uncover the ancient secrets of a giant mound shaped like a serpent.

Hunting for a legendary mass grave that could expose a dark secret of America's industrial past; using cutting-edge technology to find out why a giant lake is mysteriously disappearing high in the mountains.

Examining a set of bizarre markings that suggest a violent clash between prehistoric beasts; in California, Rob investigates to see if a strange lake is a home to alien life.

Descending into a cave 30 feet beneath Texas in search of evidence of a mass extinction event; heading to Lake Michigan to investigate an unexplained, Bermuda Triangle-like phenomenon that has caused ships to disappear for centuries.

Heading to California to investigate a network for major fault lines that could set off an unprecedented mega-quake; he explores a mysterious sinkhole that some believe is an endless pit to the center of the Earth.

Investigating a cluster of ancient ruins in New England that suggest Europeans arrived in the Americas almost 1,000 years before Columbus; heading to California where a dormant super volcano may be showing new signs of life.

Investigating the mysterious pattern of rocks at the bottom of Lake Michigan known as Underwater Stonehenge; at the notorious Alcatraz prison, Rob uses state-of-the-art technology in search of rumored escape tunnels.