If there's one thing France is famous for when it comes to wine, it's the notion of terroir.
After hundreds, sometimes thousands, of years of trial and error, French winemakers have figured out which grapes grow best in which regions, based on rainfall, sunshine, wind, soil composition and the characteristics of different grape varieties. (Not to mention the skill of the wine-grower and wine-maker.)
The idea that every nuance in a wine can be attributed to its unique place - because what happens in that place will naturally affect how the wine will taste - gave rise to one all-encompassing word: terroir (the taste of a place). Every wine thus comes from a distinct terroir and that's what makes it unique. And that is why almost all French wines are named for the place -- instead of the grape.