It was a shock to learn that right in the middle of France there's a chain of volcanoes that might erupt. Volcanologists classify the little peaks of the Chaîne des Puys as dormant, which effectively means that they have been quiet for a quite a time. Yet it also means there's a chance that at some stage they could become active. Probably suddenly and violently.
However, when I paid them a visit, a tremendous sense of tranquillity emanated from these sleeping wonders of the Auvergne. Set in the heart of one of the most picturesque provinces of France, the puys (the word for volcanoes in the dialect of the Auvergne) stretch for more or less 30km in a line north to south. There are about 80 of these hulks and they are, relatively speaking, young: they were created during the last big eruption in the area some 6,700 years ago. There's no denying that they look like volcanoes: classic cone formations with indented tops a bit like upside-down pudding basins. But coated in lush green – like so much of the landscape in verdant Auvergne – they seem benignly beautiful rather than threatening.
I had ample scope to admire them as I hiked up the highest, the Puy de Dôme. Rising 1,465m just west of the regional capital, Clermont-Ferrand, this is a striking landmark – and much more. For the Auvergnats, the Puy de Dôme is the iconic, emotive emblem of their homeland. The well-worn route to the top seemed a de facto pilgrimage trail on the afternoon I was there. I made the 45-minute walk amid happy straggles of singing children, blurs of super-fit couples, slow-and-steady elderly ramblers, and the occasional crazy biker. It seemed a minor miracle that anyone could balance on two thin wheels while proceeding up (or worse, down) at quite such unremittingly steep angles. Yet for walkers the vertiginous nature of the path gives you licence to stop without shame, gazing spellbound over the other green volcanoes, with the panorama becoming ever more staggering as you ascend.
You don't, however, have to pay homage to the Puy de Dôme on foot. A new railway opened earlier this summer, taking passengers on a slow, scenic ride to the top. Back in the early 1900s, a train service chugged ladies and gentlemen up and down the volcano. Gradually superseded by the motor car, it was closed down in the 1920s. Thereafter the winding road to the summit became more clogged with traffic. Now, in a reverse process, rail has replaced road, partly for safety reasons, partly because of environmental concerns. It's a state-of-the-art cog rail, so rather than being pulled up as a funicular, the train has a central pinion wheel that meshes with a toothed rack rail. Cleverly, the braking of descending trains produces 50 per cent of the energy for ascending services operating at the same time.
Meanwhile, the summit has been given a complete makeover. New food facilities now offer rich rewards for reaching the top – whether you walk or cheat and go by the new train. There's a top-notch gourmet restaurant, Le 1911, as well as a brasserie and a café. But you need to keep your eyes on the views: with a TV mast located here and, while I was there, work going on to build an underground station, this is not, frankly, the prettiest of places. I spent a good half-hour determinedly absorbed by the outlook, my interest heightened by the information (in English as well as French) on one of the series of noticeboards here which give chapter and verse about craters, lava flows and volcano shapes.
Such science was presented with rather more razzmatazz the next day when I visited Vulcania, a few kilometres from the foot of the Puy de Dôme. This is a go-get-all volcano theme park that dextrously manages to combine sheer entertainment with a serious role in conveying knowledge about earth sciences to the general public of all ages. The big crowd-pleasers are six shows offering a mix of impressive special effects and 4D films. I sat back to watch Le Réveil des Géants d'Auvergne (the Awakening of the Giants of the Auvergne) and was astounded by the spectacle of volcanic eruptions just outside the building and by the ensuing exodus of snakes that leapt hissing from the screen, along with other creatures. I emerged far more shaken than the cheerfully amused seven-year-olds who had been enjoying the show in the row beside me. Then I calmed down with a session in the interactive Machine Terre exhibition about the solar system, the composition of planets and the ground beneath our feet.
But of course you don't have to visit a theme park to appreciate how volcanoes shape and dramatically affect the wider landscape. I wanted to see some of the geological sights of the region – and was able to do so in style thanks to a neat new outfit. Classic car rental company ClassicArverne was launched earlier this year and offers a small stable of glorious old vehicles to drive for yourself, from an Alfa Spider to a Triumph TR4.
Tootling around the Auvergne in a red open-top 1968 Ford Mustang, I called in at Volvic just outside the eponymous village near Clermont-Ferrand. At the lively visitor centre here you learn that the water the company bottles is so pure because it takes more than three years for the rainfall in the area to permeate the lava-coated valleys around the source. I made a tour of the plant-rich vicinity and then drove on northwards, the red sports car turning heads along the way. Taking minor roads through wonderfully undulating countryside, I made for two near-fantastical water beauty spots: the Gour de Tazenat, a magma-created scar in the land that has become a mesmerisingly lovely lake; and the Méandre de Queuille, a dramatic loop in the River Sioule, caused by the fracturing of rocks from the granite plateau of the area.
My final port of call was the elegant spa town of Vichy, about a 40-minute drive north of the Chaîne des Puys. The haunt of Napoleon III in the latter half of the 19th century and capital of France during German occupation in the Second World War, it offers a great deal to see. There's a glittering, 1865 casino; a large Moorish-styled thermal spa designed in 1903; there are wonderfully opulent fin-de-siècle mansions. Best of all, though, is the Hall des Sources, a glass and wrought-iron pump room which houses outlets of Vichy's five natural springs. There is no entrance fee, but you'll need to spend €40 on a medical consultation on site if you want to drink four of the waters, which are extremely rich in minerals. However, water from Vichy's Célestins spring, elsewhere bottled and then widely exported, is freely available here. It's said to be a good aid for digestion and to have properties that can help to cure migraines. You simply help yourself from a central depot of taps.
The cupful I drank offered more than a hint of sulphur on the palate – a real flavour of the volcanic nature of this extraordinary area.
The closest airport is Clermont-Ferrand, served by Flybe (0871 700 2000; flybe.com) from Southampton (May to October). Or fly to Rodez, on Ryanair (0871 246 000; ryanair.com) from Stansted, or Lyon, on British Airways (0844 493 0787; ba.com) from Heathrow, easyJet (0843 104 5000; easyjet.com) from Gatwick, Stansted and Edinburgh, and BMI (0844 8484 888;flybmi.com) from Manchester. By train, take Eurostar (08432 186 186; eurostar.com) to Paris, then transfer to Clermont-Ferrand.
Where to stay
Des Roses et des Tours, 20 Rue Principale, Saint-Genès-du-Retz (00 33 4 73 63 68 08; des-roses-et-des-tours.fr) has B&B doubles from €85.Château la Canière, Thuret (00 33 4 73 97 98 44; chateau-la-caniere.com) has doubles from €180. La Demeure d'Hortense, 62 Avenue du Président Doumer, Vichy (00 33 4 70 96 73 66; chambre- hote-vichy.fr) has B&B doubles from €115.
What to do
Panoramique des Dômes (panoramiquedesdomes.fr). Adult return €9.50.
Vulcania (00 33 4 73 19 70; vulcania.com), St-Ours-les-Roches. Admission €21. Volvic Visitor Centre (00 33 4 73 64 51 24;espaceinfo.volvic.fr). Entry free. ClassicArverne (00 33 4 43 11 40 35; classicarverne.com).