The place:

The cellars at Leclerc Briant are crayeres: a labyrinth of chalk tunnels where constant temperature and humidity provide ideal fermentation conditions. Access requires some bottle – you descend 30m into the musty entrails using a rope and harness – but a cave expert is on hand and abseilers get an initiation certificate, a (slightly cheesy) touch much appreciated by kids.

The tasting:

Once you’re up on terra firma again, it’s inside the main house for a soothing degustation, where you’ll discover that the Leclerc Briant family don’t just have green fingers: their production methods (organic and biodynamic) are as green as the vines they’ve been cultivating since the 19th century. This means you get guilt-free Premier Crus such as La Ravinne (£22), a strong, rounded champagne made using Pinot Meunier grapes from the fields around Cumieres, and a light, floral Cuvee de Reserve Brut (£18) – perfect for an aperitif.

The lowdown:

Abseiling costs £25 and requires a separate ticket (individuals join a group). Tastings include a cellar tour (£7 a glass, £11 for two of the Monocru range, £15 for a glass of vintage bubbly no longer on sale). Reservations are imperative. Leclerc Briant, 67 Rue Chaude Ruelle, 51207 Epernay (00 33 326 544533, www.leclercbriant.com). Stay in town at the quaint Villa Eugene, former home of the founder of Mercier champagne, with its 19th-century-inspired rooms (00 33 326 324476, www. villa-eugene.com; doubles start at £90, room only).