As San Francisco’s Golden Gate Bridge celebrates its 75th birthday today, we give you this engineering marvel by numbers
* The bridge’s suspension span is 4,300 feet. This was the longest in the world until 1964
* More than 1.9 billion vehicles have crossed the bridge
* The 8,981 foot bridge took four years, four months and 26 days to build
* The bridge has been closed only three times due to weather. The longest closure was three hours, 27 minutes on 3 December 1983.

The Golden Gate Bridge
* The two main cables weigh 12, 250 tonnes and have 25,572 wires (enough to span the equator more than three times!)
* The Golden Gate Bridge spans the strait of the same name, which is approximately three miles long and one mile wide.
*A total of 600,000 rivets hold together the steel in each tower.
For more information on the Golden Gate Bridge’s 75th anniversary plans, visit: http://goldengatebridge75.org/