Svalbard is home to the Global Seed Vault, a “doomsday” bank built in 2008 that stores seeds from thousands of crop varieties and their botanical wild relatives from all over the world. The current total number of seed samples numbers some 250 million (representing 500,000 different varieties), including members of one-third of the world’s most important varieties of food crops. The vault is most commonly used in the event that any of the world’s thousand-plus collections of diverse crops accidentally lose or destroy samples – not an infrequent occurrence. The structure is about as impervious to an end-of-the-world catastrophe as possible, constructed some 120m inside a sandstone mountain and 130m above sea level, which ensures the site will stay dry even in the event that all the icecaps melt. Seeds are kept in specially constructed four-ply packets and heat-sealed to exclude moisture. For obvious reasons, the vault is closed to visitors unable to prove some specific scientific purpose.