Boyers, Pennsylvania, is home to the Iron Mountain storage facility, a former limestone mine that is now the storage site of more than 15 million photographic negatives and prints, all preserved hundreds of feet underground. This documentary, produced by the Hillman Photography Initiative, takes you inside for a glimpse at the collection and the folks who maintain it.

The photos stored at the Iron Mountain facility belong to Corbis Images, a licensing agency owned by Bill Gates. They are kept 220 feet underground because of the environmental benefits that the limestone cave provides. The natural refrigeration keeps the archive cool, which extends its life by hundreds, if not thousands, of years. [Now See This]