The Widener Library is the central part of Harvard University's library system. It is the largest university library system in the world. Though it has been there since 1915, it has gone through very few renovations, save for the restoration between 1997 and 2004 to add necessities such as air conditioning and remodeling. It was designed by the first major African-American architect, Julian F. Abele. It also houses one of the few remaining copies of the very rare Gutenberg bible.