An Aymara lady muttered to herself as she laid out a blanket on the island in the middle of the road and set out the fruit which she hoped to sell to the drivers who passed by. Down the street, a door banged, a moped started and a man wobbled off to work. The rest of the town slept on.

Uyuni was 100 miles to the north; Chile was 50 miles west, or 150 south. To the east there was little but mountains for 80 or so miles until you got to another small town named San Vincente, which became unexpectedly famous a century ago when  two North Americans were shot there. Their names were Robert LeRoy Parker and Harry Longabaugh, but they are better remembered as Butch Cassidy and the Sundance Kid.

Juanito strapped the backpacks on top of the jeep, warmed the engine, kicked the tyres and bundled us in. We tracked south again, to Chile the long way round. Out of the town and onto the plain, following a river, watched by vicuñas, the patrician cousins of the plebeian llamas. In the near distance behind them, a row of adobe huts, abandoned so long ago the roofs had rotted away. In the far distance, purple mountains speckled with grass, dusted with snow.

We crossed the river and drove into the hills. Herds of llamas with coloured ribbons tied into their wool as badges of ownership were the only sign that anyone lived for miles around. But further along, a dejected group of Aymara sheltered behind a rock from the sun. “They wait for the bus,” the guide said. “It comes once a week, but not always”. I am not sure whether he was joking.

We stopped for a break near the lip of a canyon and I scrambled along to the edge of an outcrop and peered into the depths at the deep green river slithering along the base. Then on from there to a valley littered with rock formations, rising anything up to a hundred feet, pitted in places, smooth in others, patiently whittled by centuries of wind into arresting shapes. I free-climbed a few to amuse myself; but whatever I climbed a guy from another jeep climbed something higher, and put his camera on timer and photographed himself doing star jumps at the top.

We explored lakes and rock formations, spotted flamingos, vicuñas and an occasional retiring viscacha, a big rodent which looks like a rabbit with a long bushy tail. Then, with something like a hundred miles left to run, we stopped at an eco-hotel with concrete beds, visible wires, and a toilet which the wind whistled up and rattled the seat all night.

The setting, though, was stunning. It was on the banks of Laguna Hedionda (which sounds better in Spanish than it does in translation as the Stinky Lake), the only building in sight. The lake was framed by mountains with folds of purple, brown and blue, and a sprinkle of snow on the highest peaks. On islets of mud and around the edges, mineral deposits left bold swathes of yellow and green over a white undercoat.

Vicuñas glanced from the banks at flamingos as they strode through mud, searching for food. There were dozens on the lake, noisily treading water as they built up the airspeed to fly, or gliding into land, cutting the power and braking hard with outstretched legs, then backtracking down the runway, or taxying along an islet awaiting clearance from the tower. I got closer to them than I imagined I would, but whenever I made a noise, the whole squadron scrambled, flew a circuit of the lake then cautiously landed back.

I had always wanted to see flamingos in the wild but, until then, had only caught a glimpse through the filthy window of a Sardinian public bus. I was very happy, until later in the evening when I had to attempt the hotel food. It was the worst I have had anywhere, ever. Even in Britain. The steak was perfectly cooked, if you wanted to use it for knocking in nails. The mash it was served with might have been okay, but I think that the top must have come off the salt when they seasoned it. I pushed my plate to the side and filled up on the hard bread which came with it.

We started early again the next morning, heading south through a canyon, bumping along boulders, then racing across the Siloli Desert with a great plume of sand behind us. The sky was the same unbelievable blue as a dedicated rambler’s anorak, the sand so red it might have been the road to Uluru.

Until then, we had listened to Juanito’s CD of Andean folk songs, which were about as cheerful as Country and Western but at least added local colour. Then the guide plugged in his iPod and played Eighties pop. No one else seemed to mind, but there is little that gets me down more reliably and his playlist included all of the most cynical, saccharine tracks from that horrible decade of smirking bankers, white BMW’s and big mobile phones; but I had my own iPod on quicker than a fireman can strap on his breathing apparatus and listened to Martin Garrix while the others had Tears for Fears, or some shit.

There were more rock formations in the middle of the desert, including the famous Stone Tree. With a runaway imagination, many beers and some acid you might think it looked vaguely like a tree, from a distance. If anything, it looks like a massive oyster mushroom.

Minerals in the water have turned Laguna Colorado the colour of tinned tomato soup. A flurry of flamingos came to feast on the algae, pink against rusty red. They and the mountains reflected in the surface. There were volcanic rocks scattered along the banks, poking through clumps of spiky grass. The sky was still faultlessly blue. I could have stayed and gazed across the lake all morning, and I thought that I might when the guide realised that he had left his fancy altitude-sensing watch on the bonnet at the gate to the park and went off to pace the road. Incredibly enough, he found it. Then the jeep had a flat and Juanito seemingly learned on the job how to change a wheel. I was worried that the hand-tightened nuts would work loose, the wheel would come off and the jeep would end up on its roof; but I forgot about that as we pushed on across the Altiplano.

The altimeter briefly went over 5,000 metres above sea, higher than the peak of Mont Blanc, higher than the halfway point of an Everest ascent. Desert handed over to geyser field. Smoke issued from tears in the ground, mud sputtered in pools, sulphurous skid marks stained the rocks.

Juanito pointed at the distant volcano which had been growing in the centre of the windscreen for an hour. “Chile está allá,” he said, to general incomprehension. “Other side it is Chile,” the guide clarified, and raised a collective cheer.

They dropped us beside a dead bus on a square of rough ground behind a hut with the national flag hanging from a rusty pole. It was the border post. A bored civil servant collected departure cards and put stamps in passports, which might have been hand-drawn on folded card for all the notice he took.

There was nothing much for half an hour, except roads that were as good as any in Europe – a novelty after Peru and Bolivia. If this were back home, the tabloids would get themselves apoplectic about the scope for immigrants to disappear across country. Even when we reached the official checkpoint, there was no barrier, no guard and little beyond your conscience to stop you driving straight through.

My preconceptions about Chile, grounded on the Pinochet era and encouraged by Isabel Allende, were plainly all wrong.

© Richard Senior 2015