The Barcelona Pavilion, designed by Ludwig Mies van der Rohe and Lilly Reich, was the German Pavilion for the 1929 International Exposition in Barcelona, Spain. This building was used for the official opening of the German section of the exhibition. It is an important building in the history of modern architecture, known for its simple form and its spectacular use of extravagant materials, such as marble, red onyx and travertine.