The Royal Library of Denmark, also known as the Black Diamond, is located in Copenhagen and is the national library of Denmark. It was founded in 1648 and is the largest library in the Nordic countries. The library has over 35 million items, including books, manuscripts, maps, prints, photographs, music scores, and newspapers. The library's collection is constantly growing, and it receives a copy of every Danish publication, making it a significant resource for researchers and scholars.

The library's Black Diamond building is an iconic modernist structure that was designed by the Danish architects Schmidt, Hammer, and Lassen. The building features a unique black granite exterior that sparkles in the sunlight and a bright, light-filled interior with floor-to-ceiling windows overlooking the harbor. The library's public spaces, including its exhibition areas, reading rooms, and cafe, are open to the public, and visitors are encouraged to explore the building's architecture and collections. The library also offers a range of educational programs and events for adults and children, including lectures, workshops, and guided tours.