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
Geodesic dome the greatest volume for the least surface area. The dome was successfully adopted for specialized uses, such as the 21 Distant Early Warning Line domes built in Canada in 1956, the 1958 Union Tank Car Company dome near Baton Rouge, Louisiana, designed by Thomas C. Howard of Synergetics, Inc. and specialty buildings such as the Kaiser Aluminum domes (constructed in numerous locations across the US, e.g., Virginia Beach, Virginia), auditoriums, weather observatories, and storage facilities. The dome was soon breaking records for covered surface, enclosed volume, and construction speed. Beginning in 1954, the U.S. Marines experimented with helicopter-deliverable geodesic domes.