Ancient Aliens: Crystal City Discovered Under Antarctica ( Season 18)

During an Arctic expedition, naval officer Richard Byrd makes a very unusual discovery, in this clip from Season 18, Secrets of Inner Watch all new episodes of Ancient Aliens, Fridays at 9, 8c, and next day on The HISTORY Channel website at , AncientAliens Subscribe for more from Ancient Aliens and other great The HISTORY Channel shows: Find out more about the show and watch full episodes on our site: Check out exclusive The HISTORY Channel content: History Newsletter Website Facebook Twitter Ancient Aliens explores the controversial theory that extraterrestrials have visited Earth for millions of years. The HISTORY Channel, a division of A+E Networks, is the premier destination for historical storytelling. Fro