What do we build for "ourselves?"

I kept thinking about that phrase over the National Theatre in Prague. Narodni Sobe! My usher at the National Ballet told me it translated as "We Built it for Ourselves" or "We Built it for our Nation."

I love that idea. People coming together as a body politic to create something awe-inspiring, seemingly luxurious, and breathtakingly beautiful. I've been thinking since then about what we Americans are inspired to "build for ourselves." I can picture an American family saying it about a house: "we built this for ourselves." But I can't picture Americans saying it for something we've all built as a body politic.

So often, anyone proposing increasing taxes for some purpose in America is quickly demonized. Just looking at this Czech example, you can see that a century later, the cost of that theatre has been recouped over and over and over again. Most of the time, American people want their government buildings to be completely utilitarian without any kind of magic whatsoever. It might add to the cost. Additionally, Americans are all so different that it's hard for us as a nation to find something cultural that speaks to all of us.

What's an example of something we as a people back home in America have "built for ourselves?" Roads and practical stuff don't count. I'm asking for an example that seems like a cultural extravagance. It's a greater achievement because it's harder to agree on and fund.