Is there any experience that so captures the sheer wonder of travel as waking in a sleeper train to peer out at a mysterious landscape as dawn is breaking?

Take the sleeper train from Paris to Barcelona in the summer and just as the sun comes up, as you poke your nose beyond the Pyrenees, there's an unassuming area of northern Catalonia to your right called Garrotxa. It's home to medieval stone villages, romantic abandoned farmsteads and a whole host of volcanoes. Yes, that's right: volcanoes. The only ones on mainland Spain, as it happens, and although there are 40 of them strung across the 50-square-mile Parque Natural de la Zona Volcánica de la Garrotxa, very few people (and I confess I was one of them) seem to know they're there.

However, such is the diversity of landscape crammed into the region that our week-long self-guided ramble through it began free of the merest sniff of lava. A local train to Ripoll and then a friendly taxi driver transported us the 80-odd miles north from Barcelona to the village of Molló, close to the French border. There the Hotel Calitxó resembles a Swiss chalet and affords views of a succession of mountains.

Next morning, full of muesli and yogurt and pain au chocolat, my girlfriend and I turned our backs on the Pyrenees and set off through hills that appeared to have tumbled on top of each other like carelessly piled beanbags. We carried daypacks with picnics supplied by the hotel, a map and compass, and directions to our next lodgings. An extra bounce in our stride came from the knowledge that our heavy rucksacks were already making their way there by road, a service provided by our tour operator.

So was set our pattern for the week. Each new sunny day we would walk between seven and 11 miles from one hotel or rustic inn to the next, following a pleasingly indirect route which contrived to take us roughly south-east from the Upper Garrotxa across the river Fluvià to the volcanoes on the plain below.

We were soon to learn that the joy of walking unhurriedly through this corner of Spain is that it pleases the senses on three distinct levels. First there are the edible pickings close at hand: pomegranates, chestnuts, mushrooms, rosemary, wild thyme, figs, apples and the multicoloured berries of the madroños (strawberry trees to you and me) – all growing wild and often all that remains of once flourishing farms.

Then there's the music of this particular wilderness: the wind rushing up a ravine; the gush and splutter of rivers passing below as we crossed centuries-old packhorse bridges; the fevered clanking of bells as we surprised an isolated herd of cattle; and I would have liked to have added the snuffling of wild boar, but the only one we saw had been dispatched a minute or two earlier by local hunters. We had to be content with the sizzle of onions fried by their wives in preparation for the boar-becue.

And finally there were the views. Mountains gave way to precipitous hills – the sea beyond lost in a distant haze – and at last to lush lowlands pockmarked with the textbook cones and horseshoes of volcanoes. At Can Jou, an isolated inn ("Fifteen miles to the nearest road," said Mike, the owner), we sat outside our room sipping cold drinks and absorbing a sunny vista, deep and wide and jagged. It was one of our shorter walking days – just eight miles or so up and over a rocky ridge – but this was day four and we'd got into the habit of rewarding ourselves with languid stops to drink in the scenery no matter how little walking we'd done.

But it was those volcanoes we had come for. They're dormant, rather than extinct, and were formed along a fault that developed when the African and Eurasian tectonic plates converged in the early Miocene era.

However, as the helpful woman at the Volcano Museum in Olot was quick to point out that morning, the once-fiery protuberances have been in a lava-less relationship with the region for over 11,000 years. This was particularly reassuring as we dropped down through wooded slopes into the crater of the Volcà de Santa Margarida to visit a brave little stone chapel perched in its middle.

From one vast topless cone to the next we ambled until we reached the labyrinthine village of Santa Pau, founded in the 13th century on top of its own stubby volcano. It is built from volcanic rock, which makes it appear as if it has simply grown out of the ground. It was surprising, therefore, to find ourselves dining at a restaurant, the Cal Sastre (+34 902 998479) that is a favourite with FC Barcelona footballers. That night though, we had the place to ourselves. "It's buzzing at the weekends," the waiter assured us, before launching an impromptu tasting session of the restaurant's home-made ice-creams.

It was by no means the only tasting session we enjoyed. Next morning at the wonderfully old-fashioned Hotel Cal Sastre, a few minutes from the restaurant, we tried marmalades made from local figs, apples and home-grown Seville oranges. Earlier, at Can Pei, a remote farmhouse near the village of Oix, we had sampled the owners' version of the local liqueur, ratafia, a concoction of anise and walnuts.

Elsewhere, we were reminded of the region's often-chaotic past. One rustic inn displayed poignant photographs of the proprietor's grandmother posing with Republican militia during the Spanish civil war. On another day, we walked along a precipitous gorge down which soldiers had been thrown en masse during one of Spain's interminable wars of succession.

But it was our final hotel – Els Jardins de la Martana in the medieval town of Besalú – that really thrust us back in time. The faded grandeur of this art deco mansion with its wood-panelled library made us feel like a pair of louche 20s Hollywood idols. The real star, though, was the view from our balcony of the sweeping Romanesque Bridge of the Jews, the grand entrance to the town. Fitting, we thought, that a region so rich in natural splendour should also be blessed with the odd man-made jewel.

• A seven-night Foothills of the Pyrenees tour with Inntravel (01653 617002,) costs from £758, including all meals, accommodation and luggage transfers. Eurostar trains from London to Paris cost from £69 return. The Elipsos Trenhotel "Joan Miró" Paris to Barcelona costs from £133 return, and the local train from Barcelona to Ripoll (40 minutes from Mollò) costs £12 return, through raileurope.co.uk.

Dixe Wills is the author of Tiny Campsites (Punk £10.95) published on 26 April