This royal library, also known as the Black Diamond because of its black and cube shape, is the largest library in the Nordic countries. The innovative architecture of the building, its picturesque location, and the large collection of books, newspapers and other documents that it provides are just some of the reasons why you should add this building to your list of must-visit attractions! This library also includes a restaurant and café, and two museums, one of them is the cartoon arts and the other is the National Museum of Photographs.