Underground Worlds
The Maginot Line
Season 1 Episode 8 of 10
The secrets of the largest subterranean fortress along France's border with Germany, and a look at how a unique precious mineral was discovered in Derbyshire
Underground Worlds airs on U&Yesterday HD at 7:10 AM, Thursday 12 September. (Subtitles.)
Topics
News ➝ Current Affairs
Documentary