My brother and I are both introverts. However, he loved living in big cities and I hated it.
For him, living in cities meant anonymity. He said people looked past him and he never ran into people he knew, who didn't own/work in the stores he regularly visited. In a small town, he feels like he's always noticed and constantly runs into people he knows. (Although, I think his life would be more anonymous in town if his wife and children weren't so involved in the theater community. I mean, I live in the same town and work in human resources at a place that employs over 1000 people and I recognize someone at the store maybe three or four times a year.)
For me, living in a city is a constant crush of humanity. I can feel it pushing in on me from all angles. (I'm currently in a hotel in a BIG city. I'm surrounded by humanity from five sides. Thank goodness for a window.) It's horrible and uncomfortable and I don't understand how people can stand it. Yeah, I know I miss out on lots of things, like music and theater and comic book stores, but being able to do those things a few times a month do not lessen the crush of humanity.
I have another brother. He's an extrovert. Cities or towns, he's happy because he can always find people to be with. New people, old people, whatever people. He's happy with all people.