What metaphors are used in Paris to the Moon by Adam Gopnik?

Paris is a metaphor for romantic ideals. Not just romantic in a sexual sense but in other senses as well. Paris was the principal and almost the only setting for the book. When they arrived, Paris had fallen into an end-of-the-century economic and cultural funk. It seemed to have been left behind by London and New York, but Gopnik saw this is as a positive development, at least for him and his family. It not only meant they could afford to live there, but as the rest of the world became increasingly globalized, France seemed left behind and therefore increasingly different, which Gopnik liked.