Depends on your definition but I think it's Camaiore proper. There are a handful of closer places I haven't visited that are large enough to count but I've travelled through them many times and have probably stopped in all.
I have just visited Camaiore. Quite nice, although no different from all the cities nearby (except that it seems to have an unusual density of churches, all tiny ones). My new answer is more complicated but I am quite sure I have never even travelled through Pescia so let's go with that.