I've been waiting for quite some time for the next round of grandiose engineering. By which I mean engineering that pushes the limits. The English in particular, back in the day were quite good at it, mustering thousands upon thousands of men and building trains and huge ships and factories, the like of which had never been seen before - the industrial revolution essentially. Imagine a farmer from 1750 walking into a huge factory and seeing masses of moving steel and hissing steam. It might not be a welcome sight given that it's likely just put a whole lot of people he knows out of work, but it would surely be impressive. We haven't had any for a while. The Hoover Damn was probably a candidate, given the technology of the time. The Delta works in Holland are probably a contender. It's got to the stage where even the 3 gorges dam in China, is just engineering. Sure not easy, but not grandiose. Science fiction has the grandiose in spades, my favourite I think, is the space elevator, even today though we're a while away from being able to build that though.
The American Institute Of Physics is proposing a project, it's definitely inspiring. And it's definitely on the edge of what people convenience of as possible. They think they they are capable of sending robots to the moon, getting them to build solar arrays, collect power and beam that back to earth. In a word, it's a huge project. Expensive, hell yes. Capable of removing a huge swathe of our dependency of fossil fuels though and thus worth a look. As an added bonus, we'd finally have a permanent moon base. It's border-line science fiction.