Secrets of the Underground
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.