On the rails: The 10 charming railway lines traversing 'La France profonde'

St-Gervais-les-bains – Le Fayet – Vallorcine – Martigny

The standard-gauge railway taking 19th-century tourists to see Mont Blanc terminated at St Gervais as the terrain beyond would have made anything but narrow-gauge too expensive. The train winds through deep rock cuttings and gingerly edges along shelves as it weaves through the Arve Valley to Chamonix. From lofty viaducts there are views of Mont Blanc and the Aiguilles to the east. The line then climbs through fields of lupins and cow parsley, edged with silver birch and spruce. It then descends towards Vallorcine, the last station on French soil, before the line crosses the border with Switzerland and drops down into Martigny.

Journey time 75 minutes; from £14

Beziers–Neussargues

Few lines venture as deeply into La France profonde as this switchback journey into some of the loneliest parts of the Massif Central. The line’s nickname of La Ligne des Causses comes from the arid limestone plateaux where orchids thrive. Near Tournemire-Roquefort are the limestone caves from which cheeses have been dispatched since the time of Roman emperors. Continuing along the Tarn Valley, the train passes beneath the ruined castle of Séverac-le-Château before descending into the Lot Valley. After historic Marvejols the line climbs to the Aubrac, an area of woods and stone-walled pasture. Near journey’s end is one of Eiffel’s most impressive structures, the Garabit Viaduct.

Journey time 5 hours; £31.50

Clermont-Ferrand – Limoges

A good line from which to see some of the extraordinary volcanic plugs (puys) in the Auvergne National Park. The highest, the Puy-de-Dôme at 1,463m, is clearly visible. The region has been a source of mineral water since Roman times (the line passes through Volvic) and at Laqueuille a branch goes off to the spa towns of La Bourboule and Le Mont Dore, while Limoges trains continue to Ussel. From Meymac, with its fine medieval houses and church with Black Madonna, Limoges trains head north-west through forested country, following the River Vienne to Limoges.

Journey time: 4 hours; £25.50

Villefranche – Vernet-les-Bains – La Tour de Carol

This 63km (39-mile) narrow-gauge rollercoaster journey connects two remote junctions on SNCF. From snow-melt to autumn, trains include open carriages from which to enjoy the impressive gorges, forested mountains and rolling pasture of the Cerdagne. The line crosses two spectacular viaducts: the two-tiered stone Sejourné viaduct across the River Têt which occupied 1,500 workmen for three years; and the astonishing suspension Pont Gisclard, situated in a great bowl of densely wooded hills. Trains slow across the bridge so that passengers can appreciate its construction and the precipitous view into the river valley. The best place to stop for lunch is Vauban’s Mont-Louis-la-Cabanasse, France’s highest fortress at 1,600m.

Journey time: 2 hours 45 minutes; from £17

Clermont-Ferrand – NImes

This is a leisurely journey through the Cévennes, the remote, wild country explored by Robert Louis Stevenson on the back of his donkey, Modestine, during the 1870s. Though only 303km long, the line burrows through 106 tunnels and crosses almost 1,300 bridges, including some of the most impressive viaducts on French railways, such as the edifice at Chapeauroux and the near-semicircle of Chamborigaud Viaduct. Long sections of track are built on a masonry ledge above the River Allier with glorious views along the sinuous valley. From the summit at La Bastide (1,023m) the line drops down past scant remains of coal mines to the vineyards of the coastal plain to reach Nîmes and its Roman amphitheatre.

Journey time: 5 hours 30 minutes; from £34

Chemin de Fer de la Baie de Somme

One of France’s foremost tourist railways forms a Y-shaped route astride the Baie de Somme where Jules Verne once had a holiday home. It is a perfect survivor of the hundreds of lines that served small rural communities across France in the first railway age. The trains depart from the forecourt of the SNCF station at Noyelles-sur-Mer, between Calais and Amiens. The line splits, the northern arm heading across reclaimed marsh and dunes to the fishing village of Le Crotoy and its bird sanctuary. The southern arm crosses the canal linking the sea with Abbeville to reach the resort and fishing port of St-Valery-sur-Somme, from where William the Conqueror launched his invasion of England.

Le Crotoy – Cayeux-sur-Mer: 1 hour 45 minutes; £12; 00 33 3 22 26 96 96; chemin-fer-baie-somme.asso.fr

Grenoble – BrianCon

It’s about 83km as the crow flies between the capital of the French Alps and Europe’s highest town, at 1,321m. But by rail, it’s 218km. The great detour around the highest mountains takes the line south via Aspres-sur-Buëch before turning east. At St Georges de Commiers, the extraordinary tourist railway through the Drac gorge to La Mure begins. So tortuous is the route that, at one point, a chasm is spanned by two viaducts at different levels. Later, the Briançon line crosses the Trièves plateau through alpine meadows with spectacular views of Mont Aiguille. The line skirts the Lac de Serre-Ponçon before following the valley of the Durance to Briançon.

Journey time: 3 hours 45 minutes; £26

Dijon – Morez – St Claude

This route from the historical capital of Burgundy takes you through the Jura and on to the central plateau with its excellent walking and many cave systems. It is worth pausing in Dole, birthplace of Louis Pasteur, to climb the clock tower. The highlight of the journey is the exceptional series of viaducts and tunnels that takes the railway through the spectacle-making town of Morez. The wooded hills around the town are at their most spectacular in autumn. Trains from Dijon terminate at St Claude, the world centre for briar pipe manufacture. The 14th-century cathedral of St Pierre was built on the site of the old monastery.

Journey time: 3 hours; £22

NIce – Digne

Operated by Veolia, the Chemins de Fer de Provence train threads spectacular gorges and links several places worthy of exploration over 151km. It follows the River Var for a time, the scrubby valley slopes reaching ever higher as the line climbs inland. The valley floor is often filled with lavender. In the village of Entrevaux, a zig-zag path takes you up to Vauban’s hilltop fort, used to hold German prisoners during the First World War. Huge sandstone outcrops tower over Annot, and the terrain demands steeply graded horseshoe curves to gain height. A chateau just outside Digne houses an exhibition of Tibetan art and crafts created by the explorer Alexandra David-Néel.

Journey time 3 hours 30 minutes; £14.70

Bastia – Ajaccio

Corsica’s railway network forms a lopsided Y, the left-hand fork forming a branch to Calvi off the principal Bastia-Ajaccio line. It forges a difficult passage through the island’s mountains, traversing roadless valleys and offering stupendous views of the mountains that reach over 2,500m. The heavenly scent of the maquis – a mix of arbutus, heather, juniper, laburnum, lavender, myrtle and rosemary – wafts in through the windows. Horseshoe curves help lift the line up fierce gradients – the distance, as the crow flies, between kilometre posts 91 and 98 is just 200m. Lofty viaduct abound, one across the River Vecchio designed by Eiffel. From the railway’s summit at 906m at Vizzavona station, the line drops down through chestnut forests to join the River Gravona and follows it to the sea at Ajaccio, Napoleon’s birthplace.

Journey time 3 hours 30 minutes; £19.90

More information

All fares are one way. Rail Europe (0844 848 4070; www.raileurope.co.uk); Rail Europe Travel Centre, 1 Regent Street, London SW1