Two things. First, I want to point out that "dauphin" is pronounced like "doe fawn" (but drop the w sound). Audio of someone saying, "un dauphin" here:
http://en.wiktionary.org/wiki/File:Fr-dauphin.ogg
Second, the things I used in my fantasy France game were:
The city of Rennes (
http://en.wikipedia.org/wiki/Rennes) which was actually a part of Brittany at the beginning of the 16th century, and became a part of France in 1532. It really just has some fascinating culture and history, in my opinion.
Rennes-le-Château (
http://en.wikipedia.org/wiki/Rennes-le-Ch%C3%A2teau) which is in southern France, has no association with Rennes, and has some wonderful conspiracy theories connected to it.