Season 1
S1.E0 ∙ Sneak PeakS1.E1 ∙ Capone's Escape TunnelsS1.E2 ∙ Mystery of the Serpent MoundS1.E3 ∙ America's Buried MassacreS1.E4 ∙ Rocky Mountain MonstersS1.E5 ∙ Great Lakes Bermuda TriangleS1.E6 ∙ California's Hidden DoomsdayS1.E7 ∙ Secret History of the New WorldS1.E8 ∙ American Stonehenge
Season 2
Secrets of the Underground (2017)
Using cutting-edge technologies such as ground penetrating radar (GPR), LIDAR (Light Detection and Ranging), and 3-D imaging, scientists research fascinating underworlds of secret tunnel networks, ancient structures, and bizarre geological occurrences that offer glimpses into our history.