Built during the early 1970s to protect America from nuclear war, this multibillion-dollar defence complex in remote North Dakota was operational for only a few months before it was shut down and left to deteriorate. Straight out of a sci-fi movie, the abandoned site has drawn plenty of attention over the years thanks to its unusual radar pyramid. Now, the Cold War relic has become an ultra-secure data centre for a crypto-mining company. 

Click or scroll through to take a tour of the curious site, discover the secrets of its illustrious past and find out more about its transformation...