Ancient Aliens: Holy Mysteries in Earth's Deepest Caves (Season 9) | History

The search continues with new episodes of In Search Of Fridays at 10/9c!

Some Ancient Astronaut Theorists believe alien life could be found deep within the earth's most mysterious caves in this clip from Season 9, "Forbidden Caves". #AncientAliens
Subscribe for more from Ancient Aliens and other great HISTORY shows:
http://po.st/SubscribeToHistory

Find out more about the show and watch full episodes on our site:
http://po.st/AncientAliens

Check out exclusive HISTORY content:
History Newsletter: http://po.st/HistoryNewsletter
Website - http://po.st/HistoryWeb
Facebook - http://po.st/HistoryFacebook
Twitter - http://po.st/HistoryTwitter

"Ancient Aliens" explores the controversial theory that extraterrestrials have visited Earth for millions of years.

HISTORY® is the leading destination for award-winning original series and specials that connect viewers with history in an informative, immersive, and entertaining manner across all platforms. The network’s all-original programming slate features a roster of hit series, premium documentaries, and scripted event programming.