Secrets of the Underground Season 1 Episode 2
Mystery of the Serpent Mound
Rob Nelson explores mysterious tunnels beneath Denver's airport and capitol building to investigate rumors of a secret organization operating below. In Ohio, he tries to uncover the ancient secrets of a mound shaped like a serpent.
1 - 8American StonehengeApr. 04, 2017- 1 - 7Secret History of the New WorldMar. 28, 2017
- 1 - 6California's Hidden DoomsdayMar. 21, 2017
- 1 - 5Great Lakes Bermuda TriangleMar. 14, 2017
- 1 - 4Rocky Mountain MonstersMar. 07, 2017
- 1 - 3America's Buried MassacreFeb. 28, 2017
- 1 - 2Mystery of the Serpent MoundFeb. 21, 2017
- 1 - 1Capone's Escape TunnelsFeb. 14, 2017
