The Walnut Lane Bridge in Philadelphia is a poured concrete bridge. It was completed in 1908. However, the arch of the Borovsko Bridge is under water, which I feel is unique.
I've noticed so many times how Hitler spread Germany too thin. Most especially with Operation Barbarossa but all these projects that took up resources helped too. Megalomania started and finished the Nazis to some extent. This is just my take on it as a layperson.
Yes we need to know more about the failures of the Nazi as we currently have a genocide going on by the very people that where facing one then...... history repeats itself.