Painting Golden Gate Bridge. San Francisco.

Construction: January 5, 1933 - April 19, 1937. Longest span: 4,200 ft (1,280 m). The color of the bridge is officially an orange vermillion called international orange. The color was selected by consulting architect Irving Morrow because it complements the natural surroundings and enhances the bridge's visibility in fog. The bridge was originally painted with red lead primer and a lead-based topcoat, which was touched up as required. In the mid-1960s, a program was started to improve corrosion protection by stripping the original paint and repainting the bridge with zinc silicate primer and vinyl topcoats. Since 1990 acrylic topcoats have been used instead of vinyl topcoats for air-quality reasons. The program was completed in 1995 and it is now maintained by 38 painters who touch up the paintwork where it becomes seriously coroded.