"it was a factual imitation of some Hotel de Ville in Normandy"
French Hotel de Ville
GNU Free Documentation LicenseFrench Hotel de Ville - Credit: Fanny Schertzer

 Normandy is a province of north-western France, which would have been familiar to Fitzgerald from his years with Zelda in Europe.

During World War Two, Normandy was the location of the D-Day landings which led to France's liberation.

The Hotel de Ville is the town or city hall.