Wow, an excellent list!

Right now, seriously restricted to cities (I mean, one could just say Greek Islands: Durrells*):

Venice: Death in Venice

Athens: The Colossus of Maroussi

Jerusalem: Jerusalem Poker (Edward Whittemore - but start with Sinai Tapestry)

Oxford: Gaudy Night

If you also allow Historical Novels (there are some on your list already) this could get long.

* so I did

------------------
email on profile