Montreal Olympic Stadium and surrounding structures, are but a few notable examples of the city's 20th-century architecture. Pavilions designed for the 1967 International and Universal Exposition, popularly known as Expo 67, featured a wide range of architectural designs. Though most pavilions were temporary structures, several have become landmarks, including Buckminster Fuller's geodesic dome U.S. Pavilion, now the Montreal Biosphere, and Moshe Safdie's striking Habitat 67 apartment complex. The Montreal Metro has public artwork by some of the biggest names in Quebec culture. In 2006 Montreal was named a UNESCO City of Design, only one of three design capitals of the world
Meštrović Pavilion a thickness of 57 mm (2.24 in), allowing natural light to fill the exhibition halls. The Arts Hall opened on December 1, 1938 with "A Half Century of Croatian Art", a major retrospective exhibition. The pavilion functioned as an art gallery for only three years before it was turned into a mosque in 1941, at the beginning of World War II. Architect Zvonimir Požgaj headed the project for adapting the interior of the pavilion to better suit the functions of a mosque, and Stjepan Planić designed the exterior of the mosque. Požgaj significantly altered the interior of the pavilion, introducing