A few months ago I discovered an excellent channel on YouTube called Free Documentary. The following video is a superb presentation on bridge engineering. It covers three bridges in France – the Pont du Gard, the viaduct of Garabit and the viaduct of Millau. The Pont du Gard is an amazing viaduct built by the Romans in 40-60 A.D. that still stands today. The Garabit viaduct was built by Gustave Eiffel, the builder of the Eiffel Tower in Paris.
Source: YouTube