Homesick for someplace fictional

I'm sure I'm not the only reader who gets homesick for places they've read about in books, but don't actually exist. Walking around Asheville, NC last week made me come home and read a Mitford book. Sometimes I eat croissants and pretend I'm in Three Pines. I'm still waiting for my Hogwarts letter.

What fictional towns do you get homesick for?

Note: Links to amazon.com are affiliate links. Thanks for your support.