Video: There's a fascinating backstory about the building that is now the US National Audiovisual Conservation Center, which is where the Library of Congress stores all 6.3 million pieces of the library's movie, television and sound collection. It used to be a nuclear bunker that stored $US4 billion ($5.3 billion) during the Cold War. Now, it's a one-stop shop for all things regarding film preservation and restoration, with kilometres of shelves stacked with film reels to the ceilings; all sorts of machines that can repair film, process film and print film; and any sort of video player you can imagine to play any sort of format that ever existed.