On the left bank of the Marne, Epernay rivals Reims as a center for champagne. Although it only has one-sixth of Reims's population, Epernay produces nearly as much champagne as its larger sibling. It boasts an estimated 322km (200 miles) or more of cellars and tunnels. These caves are vast vaults cut into the chalk rock on which the town is built. Represented in Epernay are such champagne companies as Moët et Chandon (the largest), Pol Roger, Mercier, and de Castellane.
If you can't get enough - follow the guide :
Maison de Pommery The cellars are underneath the Gothic style house and gardens of 'House of Pommery'. Tours are available, but reservations are recommended. Open daily from 10-6. Closed Wednesday, Saturday and Sunday in winter months.
Mumm-Mumm has been making champagne since 1827. The cellars offer a video about the manufacturing process and tours of the miles of cellars housing more the 25 million bottles of champagne. Open daily from 9-11 and 2-5, except winter months when it is closed on weekend mornings.
Piper-Heidsieck This is one of the oldest champagne houses in the world, dating to 1785. Tours of the cellars are available via electric powered cars with prerecorded audio commentary available in 7 languages. Open from 9-12 and 2-5, closed Tuesday and Wednesday in the winter.
Taittinger - This is considered one of the best French champagnes, and one of the few cellars that is still family owned. There are one hour long tours through the ancient Roman cellars which date to the 4th Century. The tours not only provide information about the champagne making process, but also about Reims' history and the Taittinger family. Open daily from 9:30-12 and 2-4:30. Closed weekends in the winter.
Veuve Cliquot-Ponsardin - Tours last an hour and a half taking you through some of the 16 miles of cellars at this champagne house dating to the mid 19th century. Visits by reservation only.

