3. Royal Gorge Bridge, near Canon City, Colorado
Unlike the two above, the Royal Gorge Bridge is a suspension bridge, not a cantilever one. It is the highest bridge of the United States, hanging 956 m above the Arkansas River. It is also one of the oldest bridges; built in just six months in 1929. This marvelous feat of engineering is a chief tourist attraction for people visiting the Colorado theme park. It was built with 1000 planks of Oregon fir, and is built to handle automobiles. The passing of vehicles makes the bridge shake and oscillate, giving an additional thrill to the experience.