The best of the regular guided tours is Mumm at 34 rue du Champ-de-Mars (March-Oct daily 9-11am & 2-5pm; Nov-Feb Mon-Fri same hours, Sat & Sun afternoons only; tour takes 45min; 25F/a?¬3.81). Established in 1827, Mumm is familiar for its red-slashed Cordon Rouge label - its un-French-sounding name is the legacy of its founders, affluent German wine-makers from the Rhine Valley. The tour is fairly informal - you can wander freely about its cellar museum and throw questions at the approachable guides - though you pick up the basics from a pre-tour video. There's not a lot of walking despite 25km of cellars and a reported 35 million bottles of wine; some of the vintage bottles date from 1911. It all ends with a generous glass of either Cordon Rouge, the populist choice; the sweeter Cordon Vert; or their Extra Dry. At Taittinger , 9 place St-NiA§aise (Mon-Fri 9.30am-noon & 2-4.30pm, Sat & Sun 9-11am & 2-5pm; Dec-Feb Mon-Fri only; tour takes 1hr; 35F/a?¬5.34), there are still more ancient caves , with doodles and carvings added by more recent workers, and statues of St Vincent and St Jean, patron saints respectively of vignerons and cellar hands.

Although founded in 1785, Piper-Heidsieck , at 51 bd Henry-Vasnier (March-Nov daily 9-11.45am & 2-5.15pm; Dec-Feb closed Tues & Wed; 40F/a?¬6.10), is better known in the New World than the Old, having been the champagne of the American movie industry since first appearing - with Laurel and Hardy - in the 1934 classic Sons of the Desert . The champagne of the Oscars gives a fair whack of sponsorship for film prizes and festivals too, and really the only folk who'll get anything out of the tour - which ends up at a gallery of celebrity snaps - are confirmed film buffs and lovers of tackiness: the antique caves are toured by automatic five-seater car shuttle resembling a ghost train. Out of the darkness and timed to a clichA©-ridden narration loom giant fibreglass grapes and vast hands armed with secateurs, or life-size badly proportioned lumpy figures positioned as cellar masters. You emerge to a glittering photo-studded foyer and a snooty atmosphere and a much-needed drink.

Top of the list of appointment-only houses is the Maison Veuve Clicquot-Ponsardin , 1 place des Droits-de-l'Homme (tel 03.26.89.54.41; free). In the early days of capitalism, the widowed Mme Clicquot not only took over her husband's business, but later bequeathed it to her business manager rather than to her children - both radical breaks with tradition. In keeping with this past, the maison is one of the least pompous and its video the best. The caves , with their horror-movie fungi, are old Gallo-Roman quarries. The House of Pommery , 5 place du GA©nA©ral-Gouraud (tel 03.26.61.62.55; 40F/a?¬6.10), also has excavated Roman quarries for its cellars; it claims - in a case of good champagne oneupmanship - to have been the first to do so. Other appointment-only maisons are Ruinart , 4 rue des CrayA?res (tel 03.26.77.51.51; 50-120F/a?¬7.62-18.29, depending on number of tastings), Charles Heidsieck , 4 bd Henry-Vasnier (tel 03.26.84.43.50; 40-60F/a?¬6.10-9.15), and Lanson , 12 bd Lundy (tel 03.26.78.50.50; 30F/a?¬4.57).

Finally, to get an overview of the various champagnes available (plus wines from all over France), it's worth visiting La Vino Cave , 43 place Drouet-d'Erlon (Mon 2.30-7.30pm, Tues-Sat 9.30am-1pm & 2.30-7.30pm), where you can also buy all the paraphernalia of the bubbly business, from champagne flutes to snazzy servers.