Spanning 541 meters over the Firth of Forth, Edinburgh’s Forth Railway Bridge became the longest cantilever bridge in the world when the future King Edward VII drove its final “golden” rivet on March 4, 1890. Its length was surpassed a few decades later by the Quebec Bridge in Canada, completed in 1919, but the Forth Bridge still holds second place, and remains an incredible feat of engineering.

Source: Incredible Photographs From The Construction Of The Forth Railway Bridge, A 19th Century Engineering Marvel