The World's Strangest Bridges: Hangzhou Bay Bridge

Background: This massive structure, which mixes cable-stayed spans and typical highway bridge elements, opened in 2008 after nearly 10 years of planning. It links the cities of Jiaxing and Ningbo, and shortens the commute between the two cities by 75 miles.

 Why It's Innovative: At 22 miles long, the Hangzhou Bay Bridge is the longest ocean-crossing bridge in the world. Engineers had to account for how Hangzhou Bay's extremely strong tides and powerful typhoons would affect the structure. From end to end, the bridge is slightly S-shaped, which helps it withstand the elements. Future plans include building a service area right in the middle of the bridge.