Mystery of the Serpent Mound

Rob Nelson explores mysterious tunnels beneath Denver's airport, capitol building, and downtown to investigate rumors of a secret organization that operates below. In Ohio, he tries to uncov... Read allRob Nelson explores mysterious tunnels beneath Denver's airport, capitol building, and downtown to investigate rumors of a secret organization that operates below. In Ohio, he tries to uncover the ancient secrets of a giant mound shaped like a serpent.Rob Nelson explores mysterious tunnels beneath Denver's airport, capitol building, and downtown to investigate rumors of a secret organization that operates below. In Ohio, he tries to uncover the ancient secrets of a giant mound shaped like a serpent.