Cool Things to Find is set in geekspace-- where interesting fact and fiction interact on equal terms-- which led me to think about a few stories which have similar spaces.
Sanders Anne Laubental's Excalibur has a vision of Mobile, Alabama (?) in heaven, where all the good things about the city exist simultaneously.
Of course, this wouldn't work as a city, but the vision is about memory and love, as is made explicit in Diane Duane's Timeheart.
In John Myers Myers' Silverlock which is about the Commonwealth, an island that has all the good stuff from fiction, there's a quote to the effect that if maintaining the place requires breaking human and natural laws, then those laws will be broken.
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