Épernay (āpĕrnāˈ) [key], town (1990 pop. 27,738), Marne dept., NE France, on the Marne River. It is, next to Reims, the largest manufacturing center for champagne wine and the headquarters of some of the oldest firms, notably Moët. The wine is stored in caves (open to tourists) which form a labyrinth some 30 mi (48 km) long in the surrounding hills. Heavy fighting there during World War I destroyed many old buildings.