In the years following WWI and WWII, Paris was the center of literary life (while it’s easy to point the city’s long and great artistic history, the American writers who went there didn’t so much go for that reason as for the favorable exchange rate – which meant that pocket change from their families in America could support a comfortable life in France).
When I was in college, Prague was the next big thing.
New York, of course, has always had a special place in literary geography.
And to this list we add… Nairobi?