Underground Marvels (2019)

S02E03 Cincinnati's Secret Caverns

Title: Cincinnati's Hidden Tunnels Plot: Beneath the bustling city of Cincinnati exists an extensive system of forgotten tunnels and caverns, holding the intriguing backstory of the city's beginnings. A team of specialists delves into this subterranean maze, aiming to uncover the identities of those who constructed it and the reasons behind its long abandonment.