The permafrost of the Cold War era ushered in mass paranoia and the construction of sites on a global scale that could withstand a nuclear holocaust and provide consistent shelter during fallout.
Many government, religious and private groups took advantage of the fear of societal extinction and constructed intricate and impenetrable structures, sometimes using mountains caves and bodies of water in the design to minimize the threat of intrusion. While Fort Knox demands notoriety as the secure location of the US depository, YouTube user Mind Warehouse embarks on an exciting journey to the corners of the Earth in unveiling wonderlands of technology and defense that were built to withstand time.
VIDEO: Discover the 10 Most Heavily Guarded Places On Earth
