The Champagne wine area is commonly divided into four official subregions.
They are the Montagne de Reims, the Vallée de la Marne, the Côte des Blancs and the Côte de Sézanne. Each has a different geographical character and a different balance of grape varieties, although Champagne producers frequently blend wines from several areas.
The Montagne de Reims is strongly associated with Pinot Noir. The Vallée de la Marne follows the Marne River and is especially associated with Pinot Meunier. The Côte des Blancs is famous for Chardonnay, while the Côte de Sézanne lies south of it and also grows substantial Chardonnay.
These four names are wine-geographical groupings, not four separate appellations. Champagne’s protected appellation covers the wider legally defined production zone, including areas such as the Aube, which is often discussed separately from the four core subregions.