The Hoover Dam is an exceptional piece of American ingenuity that is unmatched in its success. What I find so amazing is that we able to pull together all of the different stakeholders to create this dam in a way that had maximum benefit. Without each stakeholder finding some value it in then they would have been unlikely to support it.
The other aspect of this dam is that it was designed with a level of genius in mind. How someone went from a conceptual idea to the hundreds of thousands of working parts is amazing. While they may have though it up putting it all together is a different story.