No matter which bunker you pick, you'll bag yourself 2,080 square feet (193sqm) of interior space. You wouldn't have to worry about safety, either, since the reinforced concrete bunkers were designed to be impenetrable. Their history dates back to 1942, just after the United States entered the Second World War.
The site was established as the US Army's Black Hills Ordnance Depot and the domed bunkers were built to store weapons and ammunition. The military base was closed in 1967 and the site was abandoned, until real estate mogul, Robert Vicino, bought the land from a local cattle rancher and set about creating the world's most sought-after network of apocalypse shelters.