I lived in NYC for almost 20 years, and only now realize how traumatizing it was for my senses--so much going on, so much amazing and awful stuff. Nearly four years later, I'm probably still processing. I don't think huge cities like NYC and Seoul will be able to continue the way they have, largely due to global warming and related food shortages. But pretty much any small town with a city center--ones not designed around cars, and they're all over the world--is planned in a way that avoids suburban isolation.