Tell almost anyone you're going to the Trient valley and they immediately ask, "Where?" It's possibly Switzerland's best-kept secret: a lovely, unspoilt valley running from Martigny to the border town of La Châtelard, and on to Chamonix in France. Time was when the Trient valley was well-known as a health resort, especially by the English; that came to end in 1918, but the spectacular scenery and the pure mountain air are still there.
From the Rhone valley, the Trient looks totally inaccessible, guarded as it is by an impressive steep-sided gorge. For a splendid view straight down to the river, take the Mont Blanc Express from Martigny (how they built the railway line at all in such steep country is miracle). The train goes all the way to Chamonix, normally taking an hour and a half - though I should mention here that there's a replacement bus service on the French side until next summer as the line's being upgraded.
At Salvan, one of several charming little villages on the Marécottes plateau, you'll find the Marconi museum. Marconi, a Nobel prizewinner for the development of radio, did his first experiments with wireless in this area, and the museum was set up in 1996. This year it has a special exhibition on the sinking of the Titanic: his radio system played a major role (constantly sending SOS messages) in enabling so many people to be saved. The museum is a gem, with a wonderful display of old radio equipment, the first mobile phone (the size of a briefcase!) and an attractive set of short video clips on Marconi's life and work. Just up the hill is the Bergère rock, where he made his first wireless communication over just a few metres.
The high point is a trip to Lac Emosson, a huge reservoir at almost 2000 metres nestling under the mountain forming the border with France. Getting up there is an adventure in itself. You get off the Mont Blanc Express at La Châtelard and follow the signs to the steepest funicular you're ever likely to travel on. At the top you change to the little train that chugs round the mountain to the dam, giving you spectacular views of the valley below and the mountains above – including the great Mont Blanc massif itself. Then you change again to the Minifunic, which takes you up the last stretch to a viewpoint 30 m above the dam, giving you another fantastic view. This gives you a perfect excuse to linger on the terrace of the restaurant and enjoy a typical Valais apéro. You could also drive up, but it's not half as much fun!
There's a whole range of other things to do and see as well. You can go canyoning in the gorge, if you have the nerve, or swimming in the beautiful natural rock swimming pool at Les Marécottes, which village also has an alpine zoo. There are hiking and biking trails in every direction. Or you visit the Trient glacier, reputed to be one of the most beautiful in the Alps. This valley is also popular as an off-the-beaten-track resort for skiing in the winter, and it's worth looking out for special offers.
The Mont Blanc Express is the most direct way of travelling through the main valley. By car, you can take the little road from Martigny across the gorge to Les Marécottes, which is where it stops, or else the main road to Col de la Forclaz, Trient and La Châtelard. There's a lovely three-star chalet-style hotel in Les Marécottes, "Aux Mille Etoiles", with a large covered swimming pool, another family-run vegetarian hotel called "Les Granges", and a selection of guesthouses and holiday flats. Plans to build more hotels are on the way.