This is a long shot, but I know from the Terry Pratchett thread that some of you vipers are well read, and like fantasy.
I read a book a while ago which was set in a city, outside of which lay a vast rib cage, of a creature that had died centuries before. It was so large that it had become a feature of the landscape, as in people would meet up or go for walks there.
I can’t remember any other details, other than that rather brilliant idea, and I would love to re read it.
Anyone find this familiar?