Pamban Bridge, India

Built in 1914, Pamban Bridge was India’s first sea bridge. (It was the longest, too, until 2010 when the Bandra-Worli Sea Link opened.) It has a staggering number of piers — 143! — and opens up in the middle to allow ferries and other ships to pass through, which happens about 10-15 times per month. While you might not be too keen to take such a long journey across the sea, for almost 75 years it was the only way to get from Rameswaram Island to the mainland. What earns it the “extreme” moniker, outside of it dangling over the sea? Well, the bridge is located in the second-most corrosive environment in an area that is known for its cyclone-level winds.