Built in 1963, this extraordinary piece of architecture is the largest building in the world designed for the preservation of rare manuscripts. The windowless cube has walls of Danby marble that subdue the effects of light, while inside the glass stack tower displays sculptural shelves of books, including one of only 48 surviving Gutenberg Bibles (1455) and original manuscripts by Charles Dickens, Benjamin Franklin and Goethe. Open weekends when there is an exhibition.
In the center a sunken courtyard contains sculptures by Isamu Noguchi representing time (the pyramid), the sun (the circle) and chance (the cube). The library's 50-year-old heating and cooling systems were completely replaced in 2015–16, and new classrooms added.