Premise: A fascinating new world has emerged for scientists to study, and it's just beneath their feet. With the emergence of cutting-edge technologies such as ground penetrating radar, LIDAR (Light Detection and Ranging), and 3-D imaging, scientists are now able to research underworlds of secret tunnel networks, ancient structures, and bizarre geological occurrences that offer glimpses into the past. In ``Secrets of the Underground,'' Rob Nelson, an ecologist by trade and an explorer by pastime, travels the country to investigate long-lost, subterranean phenomena. Nelson looks at all things hidden, covert and unfamiliar, from intricate and forgotten sewers and caves to lost civilizations and structures.
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.