Denver's Forgotten Underground - Atlas Obscura
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Denver, Colorado

Denver's Forgotten Underground

An exclusive tunnel spotting tour exploring the mysterious past beneath our feet.

The history of Denver is inseparable from the massive hidden tunnel network that lies just below your feet. 

Learn to spot the remnants of Denver’s underground life on our walking tour with historian Tracy Beach, author of The Tunnels Under Our Feet: Colorado's Forgotten Hollow Sidewalks. During this tour, Tracy will lead you down the same path that landed her on The Science Channel's hit show, The Secrets of the Underground. After our exclusive tunnel spotting tour, we’ll rendezvous at The Rio Grande restaurant. Grab a cocktail and settle in as Tracy shares photos and stories, revealing more of Denver’s forgotten underground past.  

Note: this tour encompasses the history of the tunnels and reveals the remnants still visible from the street. We will not be entering the tunnels due to safety issues.

Additional details:

  • The 3:00 and 4:00 PM tours both include a one hour walking tour and a one hour presentation of stories and photos. If you choose the 3:00 PM tour, you’ll begin with the walking tour. If you choose the 4:00 PM, you’ll start with the presentation. All tours will start from the Rio Grande.  
  • Please meet at The Rio Grande restaurant 15 minutes before your tour time, 1525 Blake Street Denver, CO 80202
  • Event will run rain or shine.
  • This event is suitable for ages 12+.
  • ADA: Some parts of the tour will not be wheelchair accessible. We apologize for the inconvenience.
  • Please contact for additional accessibility information/questions.
  • Tracy’s book will be available for purchase at the event.


Email James O'Neill at

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Advance tickets only. All sales final. No refunds or exchanges.