Beinecke Rare Book and Manuscript Library at Yale University — New Haven, America
Everything about this building has been specially designed to preserve its contents. The walls themselves are made from incredibly thin marble, which allows light to shine through, but will not damage the books. The centre glass box is sealed and can be filled with fire-supressing gas should there be an alarm. It opened in 1963, and is one of the largest libraries in the world dedicated to preserving rare books and manuscripts.