Che Guevara rode through on his 9000-mile motorcycle odyssey. Outlaws Butch Cassidy and the Sundance Kid bought a ranch here with their ill-gotten gains. Several thousand Scots emigrated here in the 19th and 20th centuries, and writer Paul Theroux arrived on the steam-powered Old Patagonia Express. It was reading British writer-explorer Bruce Chatwin’s 1977 account of his journey into South America’s southern tip – In Patagonia – which first stirred my interest in the place. But the distance from Britain (about 8500 miles), the cost of getting there and the fact that nobody else shared my fascination with one of the world’s last great wilderness areas delayed my visit by about 30 years.

It was worth every minute of that wait. A kaleidoscope of glaciers and granite massifs, lakes in every hue of blue surrounded by snow-capped volcanoes, splintered jigsaw puzzles of fjords, islets and icebergs, Patagonia really does feel like the edge of the planet. A landscape bathed in iridescent light and whipped by wild winds, it is a region of vast horizons straddling Chile and Argentina, squeezed between the Atlantic and Pacific oceans, and split by the Andes.

Chile’s Lake District is the gateway to north-western Patagonia, an easy and relaxing introduction to an area which becomes wilder as you travel south. Pretty Puerto Varas is the main centre on Lago Llanquihue, the second biggest lake in Chile. Across the water, in which children swim to cool off and limber young men spend their days windsurfing, stand the three snow-capped volcanoes of Osorno, Calbuco and Puntiagudo.

The town itself is small enough to explore in a day. Quaint independent shops, a long lakeside promenade dotted with ice-cream carts and guitar players, and restaurants serving everything from barbecued lamb to local seafood all make Varas an easy base from which to explore. The Lake District is all about the outdoors, and you can buy every conceivable trip from one of the many adventure companies operating out of here. The spectacular geography provides opportunities for fly fishing, trekking, skiing, volcano climbing, horse riding, mountain biking, windsurfing and ice climbing.

Walking up one of the volcanoes requires a pre-dawn start and a lengthy uphill slog. Not for the faint-hearted. Instead we took a catamaran trip across Lago Todos Los Santos – known locally as the Emerald Lake because of its striking colour. The boat dropped us at the far side of the lake for three hours, which we spent hiking trails in the hot and dusty hills. Deep forest provided some protection from the fierce sun, but huge sand flies the size of cockroaches bothered us. A dip in the lake with some local children cooled us down before we caught our catamaran back to Varas where, of course, a hearty dinner was required.

The lakeside restaurant Mediterraneo (at Santa Rosa 68), has the best open-air terrace in Varas, with pasta, fish, salads and homemade soups on the menu. Imperial 605 (the address as well as the name of the restaurant), specialises in local seasonal food such as wild salmon baked in honey. Seafood is a speciality on Chile’s Pacific coast: lunch or dinner options at Chamaca restaurant in the town centre include squid, scallops, king crab, razor clams with Parmesan and the local Kunstmann beer, for about £20 per head.

White water rafting on Rio Petrohue is a popular excursion – an exhilarating few hours with the adrenalin pumping hard on a bumpy journey downriver below steep banks of virgin beech forest. We were picked up and dropped off from our accommodation in Varas and spent five hours rafting, which included a picnic lunch. Getting tipped out of the inflatable raft on one of the rapids hurt a bit but the river water felt warmer than the air, so it was like submerging into a soothing bath.

Because of its remoteness and inaccessibility, Patagonia has always been a place of myths and legends, like Timbuktu or Shangri-la. These legends abound in Chiloe Island, a three-hour drive and short ferry ride from Varas. The island retains many unique traditions which set it apart from the Chilean mainland, including a firm belief in mermaids, witchcraft and many mythical figures. It is also rich in wildlife: condors, black-necked swans, eagles, sea lions, penguins and dolphins are all common.

We did a 14-hour excursion from Varas to Chiloe Island, taking in the fruit and vegetable market, a rare penguin colony on the island’s west coast, a stroll along a 10-kilometre white sand beach, and a visit to one of the fishing villages where unique houses are built on stilts.

Back on the mainland, we continued our journey south into the true heart of Patagonia. Destination: the Parque Nacional Torres del Paine, a wind-whipped wilderness whose heart is the Torres, three giant granite columns rising vertically from the Paine massif. Hours and hours on a bus took us across a dust-soaked steppe stretching to the horizon, populated only by ubiquitous sheep, skittish guacanos (which looks like a cross between a llama and a deer), and the occasional man on horseback. Getting off the box for brief pit-stops introduced us to the wild winds which chased us round southern Patagonia – winds which one observer described as a “living thing” causing birds to fly backwards and trees to grow horizontally.

There are many ways to experience this oil-, gold- and gas-rich part of the world. We chose an organised five-day trekking package with Cascada Travel, staying at an “eco camp” at the base of the Torres in unique two-person plastic igloos. The accommodation was surprisingly comfortable – single beds rather than sleeping bags on the floor – and the view through our plastic window of the Torres high above us will never be beaten.

The eco camp was our base, where we enjoyed hearty home-cooked meals in the dining “dome” and cosy evenings round the wood-burning stove in the “R&R dome”, swapping stories of our day’s adventures over bottles of Chilean red with fellow travellers from Scotland, Ireland, Canada and Italy. A tipsy walk back to the “igloo” revealed the clearest starry night sky I have ever seen and the monolithic shadows of the Torres standing like three hunched giants in cloaks.

A mini bus took us to our walk start point each day, then met us and delivered us home in time for dinner after day-hikes of between four and eight hours. The geography of one two-day walk meant we stayed a night in a shared dormitory in a “refugio”, a simple hostel/hotel. There isn’t a huge choice of accommodation in the Torres del Paine park, and the further you travel, the more likely you are to have to stay at a refugio. Manage your expectations: accommodation is basic, and the fact that the nearest shop is a five-hour drive away means food is largely canned, packet and powdered.

A small price to pay, however, for the chance to trek round the majestic Torres in a park which, even in high season, often seems near-deserted. Ideally you need a week to 10 days to see the park, which has about 250km of trails. The weather is unpredictable and some of the trekking is punishing, with steep climbs and downhill sections sometimes on scree and often in violent winds. We experienced blistering sun, wild squally winds and a little rain, but thankfully no snow. It’s easy to take a wrong turn and end up on a very scary precipice, and since horseback and helicopter are the only ways out of the park in an emergency, it’s wise to stay safe.

The most popular trek is El Circuito, which takes five to six days but is often closed because of snow in the winter. Sections of it are tough. The W is a popular alternative to El Circuito, and can be completed in four to five days. One highlight is the Grey Glacier: we hiked along Lake Grey to the face of the glacier then boarded a boat which took us to within 500 yards of the edge of the glacier. What had looked like a small ledge from the cliffs above was, close up, a 200ft tall wall of white-blue ice. We sailed beside the glacier wearing copious layers of clothing and sipping whisky or pisco sour (Chile’s national cocktail – a potent mix of brandy, lemon, sugar and egg white). There are only two boat trips in the park, both well worth doing. The trip beside the Grey Glacier is one, the other is across Lake Pehoe.

Our treks took us across green valleys carpeted with wild flowers where we saw condors, wild horses, eagles, rheas, ibis, flamingos and parakeets. With each new walk the superlatives accumulated – biggest, best, wildest, bluest, highest, most remote. So many places in the world have been spoiled, but Patagonia? Not at all. Not yet. What Chatwin described as a vast, lonely wilderness restores some hope for the planet, a reassurance, that there are corners of it where nature still has the upper hand.