Duff Hart-Davis roughed it in the rugged terrain of the Alto Minho
No curled-up sandwiches for us. Waiting high in the mountains was a sumptuous and beautifully laid-out picnic lunch. We feasted off spiced chicken, local ham and cheese, three different salads, then almond cakes and fruit, all washed down by vinho verde.

A sybaritic walking tour may sound like a contradiction in terms; but a combination of hard exercise and soft living is exactly what you get from the Alternative Travel Group, which long ago realised that an army marches on its stomach. The company sends out parties to numerous wild areas of Europe: you can either form your own band, or join a heterogeneous group. We took the first option and recruited 14 friends to hike through the upland wilderness of the Alto Minho, in northern Portugal.

Set down by minibus in the village of Castro Laboreiro, we left civilisation behind within minutes, and struck off into the spectacularly desolate rock-scape of the Peneda-Geres national park. In this 280-square-mile sanctuary vast outcrops of granite dominate the skyline, and smooth boulders, like Henry Moore sculptures but 50 times larger, dot the lower slopes.

Our tour leader, Edward Granville - barely 25, but already much travelled - not only spoke fluent Portuguese, having read the language at Oxford University; he had also walked our route in advance, and was full of information on any topic we raised.

At an earlier briefing he had urged everyone to wear boots and long trousers, rather than trainers and shorts; and now the wisdom of his advice was evident, for the tracks were shod with uneven slabs of granite, and we were often brushing through prickly gorse.

But where were the fauna? The park harbours roe deer, boar, skunks and even a few wolves - yet the only animals we saw were wild ponies and the fine, long-horned cattle that farmers take up to graze on the summer pastures. A two-hour tramp brought us over a ridge and down to the first of many memorable picnics. Afterwards, groaning, we climbed hard again, now on one of the pilgrim tracks leading to the great shrine of Peneda. In mid- afternoon thunderclouds massed ahead of us, and Edward, marshalling us carefully, recalled how three people in a previous party had been knocked down by lightning.

When the storm hit us, nobody was struck, but all were soaked. It was with no mean relief that we at last sighted the terracotta roofs of our destination huddled at the foot of a gigantic cliff far below, and heard the brazen chimes of a church clock come clanging up the rocks to greet us.

The village of Peneda is merely a scatter of houses, and a few barrack- like blocks built to house pilgrims. The star attraction is its church, huge, white, and approached by a monumental Via da Gloria - a processional way rising through flight after flight of granite steps and flanked by 21 lesser shrines with conical roofs. Legend has it that the church was founded in August 1220, after a shepherdess saw a vision of the Virgin during a freak snowstorm. Today (Edward told us) the place seethes with visitors over the autumn festival, but in summer it was almost deserted. Only a single penitent was painfully hauling herself up the granite staircases on padded knees, with a pair of improbable, fluffy orange slippers bobbing up behind her.

We stayed in one of the dormitory blocks, now converted into comfortable rooms, and dried out round a blazing fire. Dinner - another meal to remember - included that Portuguese staple, thick vegetable soup, and kid roasted in a wood-fired oven.

Thereafter our route took us steadily down into softer country, through glorious beech and pine woods, along innumerable little terraces carved from the hillsides and past hundreds of espigueiros - curious, stone-built granaries used for storing maize, raised on staddle-stones to keep out rats, and surmounted by pediments and crosses, as if they were little tombs.

Vines grew everywhere: vines by the million, often trained on wires supported by slender posts of hewn granite 10ft tall. In the town of Arcos de Valdevez peaches, oranges and grapefruit loaded the trees on the lawn of our hotel, and we scattered the resident watersnakes to swim in the lovely, fast- flowing river Vez, cold, clear and green.

By the time we reached Ponte de Lima, on a golden evening, we had walked between 10 and 15 miles a day for six consecutive days, and we subsided gratefully into a stylish 17th-century mansion, home of Dona Gracinda, whose banquet of a dinner put a fitting seal on our gastronomic extravagances.

Studied in cold blood on a map, our itinerary did not look very impressive; but our young team had looked after us admirably, never getting lost, never faltering in their organisation. We ourselves had gained a little in fitness; and, like all good trips, ours had been a journey to another world.

The Alternative Travel Group Ltd, 69-71 Banbury Road, Oxford OX2 6PE (01865 513333). Duff Hart-Davis's eight-day trip cost pounds 1,125 per person, including accommodation, food, wine and transport within Portugal, but not flights.