The Golden Gate bridge spans the Golden Gate strait, connecting the city of San Francisco to Marin County. Construction of the bridge began in 1933 and was completed in 1937 at a cost of $903 million. At the time of it's completion it was the largest suspension bridge span in the world. It remains the second largest suspension bridge span in the United States.
The Tower bridge spans the river Thames linking the London boroughs Tower Hamlets and Southwark. The bridge, a combination bascule and suspension bridge, opened in 1894.