It’s an unholy combination. A pompous civil servant with a shiny uniform, power complex and savagely remote mountain posting. The moustachioed officer scowls, stamps my passport and, with an expression of utter contempt, brushes me out of the door. Welcome to Argentina.
"The officer has just arrived from Buenos Aires," explains our guide, Chino, as we exit the customs post into a vast mountain plain raked by brittle sunlight and freezing winds. "He is feeling the puna (altitude)."
Good. It’s nice to know he’s suffering. We’re not thank you señor. As part of a trans-Andean journey, we’ve spent days acclimatising to the paper thin, oxygen deprived air encountered during crossings of South America’s 22,000ft spine from Chile’s Atacama Desert to Argentina’s Salta province.
If it sounds like an expedition for mountaineers with iron constitutions and ice-licked eyebrows, think again. Wilderness experts Explora blends the seriously wild with the gloriously cushy. Its answer to Everest Base Camp is Hotel de Larache, a low-level ranch in the oasis town of St Pedro de Atacama - a chic riot of squashy sofas, bleached wood and tasteful weaves.
The coolly contemporary luxury comes with elegy inducing views of 22 volcanoes. But just as remarkable are the swimming facilities. No, really. The hotel has four identical pools. Each is an al fresco art installation, juxtaposing turquoise water with white cube saunas and square modernist arches. In the Atacama, the driest desert on earth - fifty times more arid than Death Valley - the pools both spectacular and truly decadent.
Our acclimatisation kicks off at 8,000ft starting 3,200ft higher each day. We begin with a soft cycle ride into St Pedro, a one-llama town with a main street called Caracoles (snail), and a growing reputation as a hub for desert adventures. The pedal is a mere aperitif for an afternoon trek through Valle de La Luna. It is a world that assaults the senses: pink and orange cliffs sandwiched between black sand and cyan blue sky; snow flakes that turn out to be evaporating salt; and rocks that make noises.
"Wait for a temperature change," says Chino. "You can hear them groan and crack."
And that’s just for starters. Crossing a ridge we find a landscape worthy of a NASA mission. Above a valley floor like overcooked fruit crumble, vast battalions of jagged caramel rocks march towards the horizon. "Nobody will believe these colours," exclaims a photographer in our group. "I’ll have to de-saturate the photographs." He’s not exaggerating. Around sunset, as a warm wind is whipped up by Pacific high pressure, the whole world ignites into shimmering gold.
Each acclimatization if breathtakingly different. At 11,500ft we hike alongside the Puritama River, a dribble of sweat through a crimson gorge lined with chilca and pampas grasses and gooey cactus fruit. Explora has alchemised the ladder of thermal pools into an outdoor spa with a discreet changing room, fluffy robes and slippers. We emerge from a muscle-relaxing soak to find a table spread with a gingham cloth, and iced wine, beer and gourmet canapés. The Atacama’s a Daliesque creation of the weird and the wonderful, but in the brutal, otherworldly wilderness, this is the most surreal sight so far.
Next day runs it close. As final altitude preparation, we drive to the Tatio geysers. At 13,780ft, they’re some of the highest on earth – and surely some of the most beautiful, swaddled by volcanic cones feathered like giant mugs of latte. The normal laws of physics do not appear to apply. Every nine minutes the magma chambers spew boiling water and steam onto land covered in ice, and littered with clumps of grass blackened by invisible heat. The sun burns your nose while the air freezes your fingers. It’s confusing.
And the geysers aren’t the only things wheezing. Our walk around Mt Copa Coya up to 15,000ft is an early taste of senility. We shuffle along, our strides shortening as our breaths quicken. Foreheads thump. As smoke drifts towards us, our guide digs into his rucksack.
"Are you radioing for help?"
"No, taking a picture. The smoke could be Bolivian drug runners. We’re crossing a mountain route."
Oh Lord, it wouldn’t happen in the Yorkshire Dales. But nor would our lungs be this strong. We stumble to the finish, and are declared fit to cross the Andes.
We depart early next morning, queuing up behind Bolivian lorries and Brazilian busses at an immigration post 125 miles from the isolated border. Its missing persons posters suggest this is wild and woolly territory, particularly the image of Juan Pablo Uride with his Charles Bronson eyes and viciously scarred neck.
Heading east we’re accompanied by a CD of panpipes and a chain of volcanoes, spiking above a sloping plain of purple and black lava. Hell it’s a brutal landscape. Gravel soccer pitches are marked out in sulphur, alfalfa plantations withered by arsenic and distant dots on the salt lake’s shore are mines that make this region ‘The Middle East of lithium’ while taking a relentless gulp on precious water supplies.
After passing the new Atacama Cosmology Telescope trained on the world’s clearest skies, we cross the Inca trail as it heads towards sacred Mt Llullaillaco, the planet’s second highest volcano. Its 22,000ft summit was where three tiny, cryogenically preserved corpses were discovered in 1999. The Inca children had been sedated with alcohol and left as frozen sacrifices to the gods.
It’s warmer where we stop to hike. But only just. At 14,000ft, we swap wheels for boots and stride out in a minus 15C wind chill. No one notices. The scenery is astounding: cappuccino coloured cones encircle emerald lagoons and scarlet plains frescoed with yellow scrub. We stop in a sheltered sun trap for the most scenic, and highest quality, picnic of our lives: salmon and prawn ceviche, followed by plump chicken, lubricated with a 2004 Cabernet Sauvignon and fresh strawberry juice.
Life’s a little more puritan at the corrugated iron Chilean border post.
"We go for days, even weeks, without cars," sighs the young guard. "If it snows, we’re stuck."
Not today. We zip through ten miles of no-man’s land - a sign reveals it’s 181 miles to our finish in Salta city – and enter Argentina. Almost immediately the barren, Hades-like border plain changes to a quilt of cocoa and mustard hills, crossed by the recently re-launched ‘Train to the Clouds’ and drizzled with llama. As light fades, the day offers a final thrill with the switchbacks and nerve jangling drops – I stopped counting at 100 – of Abra del Acay. At its 16,000ft peak, there’s not enough oxygen to light a celebratory cigarette. The paper huffs and crinkles in defeat.
The night is spent in a staggeringly remote, ludicrously luxurious campsite. Our pimped goat herder’s hut has a glass-sided power shower and slate floors alongside tents with silk-lined sleeping bags, alpaca hair blankets and chocolates on the pillows. Heavens knows what Bertha the goat herder makes of it. She lives in a basic stone house across the road; 20km from nearest human, with a bed awaiting repair after rats chewed the frame.
Directly outside the Calchaquies River is narrow enough to leap, but as descend under the trip’s first clouds – Atlantic warm fronts rule on this side of the Andes– it widens into a Nile-like ribbon of fertility, irrigating fields of quinoa and corn along ancient canals. Its flow dissects red sedimentary rocks squashed like raspberry sponge that host 600-year-old Inca granaries and 21st century political graffiti: Walta Wayar Gobernater!
We drop. Temperatures rise. In colonial Cachi we seek relief in 60p beers and 60p packets of Marlborough before ambling around the town’s extraordinary cemetery. Some inmates have tatty breezeblock headstones, others have houses with tiles, doors and spires, but all are garlanded with flowers cut from plastic bags and all enjoy epic views of 20,933ft Cumbre Libertador: the democracy of death.
After hiking around massive silvery cactus and sleeping in an elegantly converted schoolhouse above the Calchaquies Valley - possibly South America’s best bath tub view - we reach Piedra Del Molino, the edge of the Andean Plateau. We turn onto the snaking road, but it feels more like motorised abseiling. Just thirty-five minutes later we’ve traded the ubiquitous rock for fecund subtropical vegetation. Houses have front lawns, roads have traffic lights – the only ones of the crossing – and Salta is buzzing. In its museum we find Los Niños, the three mummified children from Mt Llullaillaco. They appear to be merely asleep: serene eerie reminders of the extraordinary land we’ve left behind.