This is the largest of Italy's national libraries and one of the most important in Europe. In 1966, a major flood of the Arno River in Florence devastated nearly one third of the National Central Library's holdings; never had so many priceless books been water-damaged in one event. The conservation techniques used at that time were not up to the task of rescuing and preserving books on such a large scale. Today's library conservation practices were born in the aftermath of the 1966 flood. We visited the library's conservation lab, housed in an old convent, and I photographed the continuing restoration efforts 52 years after the flood. A mark on the main entrance to the library showed us the flood's high point several feet above the top of my outstretched hand.