Secrets Underground

Rob Nelson investigates the vast mysterious tunnels that lie beneath Denver's airport, probing their hidden passages. He then journeys further to Ohio to uncover the secrets of the giant imposing serpent‑shaped mound, a massive earthwork that has long puzzled researchers.

Mystery of the Serpent Mound is a television programme presented as a single episode, falling within the mystery genre. The show follows presenter Rob Nelson as he pursues unexplained phenomena, moving from one enigmatic location to another in a concise, investigative format. The episode opens with Nelson delving into a network of puzzling tunnels that lie beneath Denver’s international airport. He examines the hidden passages, questioning their purpose and the reasons they remain concealed from public knowledge. His on‑site inquiries aim to shed light on the origins and possible functions of these subterranean corridors. From Denver, Nelson’s investigation shifts to the Midwestern United States, where he travels to Ohio to explore a massive earthwork known as the serpent mound. This towering, snake‑shaped formation has long attracted speculation, and Nelson seeks to uncover the story behind its construction and the cultural significance it may hold. His exploration includes on‑location footage and interviews that aim to piece together the mound’s mysterious past. Throughout the programme, Nelson’s methodical approach links two seemingly unrelated mysteries—the underground tunnels and the colossal serpent mound—highlighting a common thread of unanswered questions. By the episode’s conclusion, viewers are left with a clearer picture of each site’s intrigue, even as many of the deeper secrets remain unresolved.