I just received a copy from the Underworld World documentary series produces by Phoenix Television .
Hidden beneath our feet lie extraordinary spaces, caves and tunnels. They’ve been designed and built by us as well formed by nature. But how were they created and adapted? By whom, and why? For centuries, subterranean structures have captured our imagination. Now we’re going further and deeper to unearth the stories, the mysteries and the secrets of Underground Worlds.
Underground Worlds. Fort Reuenthal. Switzerland. February 5, 2019
The Sonnenberg tunnel in Lucerne during the largest civil defense exercise ever held in the country. From 16 to 21 November 1987, almost 1200 men and women converted a motorway tunnel into perhaps the world’s largest bunker structure on www.didierruef.com
More pictures on the Swiss Bunkers www.didierruef.com