Science Ch. - Secrets of the Underground Series 1 (2017) Part 2 Mystery of the Serpent Mound

Secrets of the Underground Series 1

Rob Nelson, an ecologist by trade and an explorer by pastime, travels the country to investigate long-lost, subterranean phenomena

Part 2 Mystery of the Serpent Mound

Exploring mysterious tunnels beneath Denver's airport, capitol building and downtown to investigate rumors of a secret organization that operates below; in Ohio, trying to uncover the ancient secrets of a giant mound shaped like a serpent.

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