U-Verlagerung R
WW2-era underground factory built in an old slate quarry, to produce fuel for V2 rockets. It was captured intact by the Americans …
Schiefergrube U
Slate quarry
Les Catacombes de Paris
What more do I need to say? The Paris Catacombs are the underground Walhalla for most explorers. Over 300km of old tunnels …
Limestone Quarry
Here’s one we’ve been thinking of doing for a long, long time now. Under the Belgian/Dutch border lie hundreds and hundreds and …