The lake rippled with velvet shades of crimson, fringed by pearls of arctic white borax. Around it hung a mantle of lime-green grasses from which, like a high collar, rose the ashen flanks of Mount Licancabur. Against this iridescent palette of colour stood the llama, sporting an ineffable pout of disdain.

Few venture into this corner of Bolivia. “The difficulties of independent travel in the Far South-West cannot be overstressed,” warns the normally gung-ho Lonely Planet guide. Given the altitude and lack of communications and watering holes, the warning is best heeded.

I had acclimatised gently, courtesy of the wonderful Explora hotel on the Chilean side of the Andes. San Pedro de Atacama, with tour agents in place of gunslingers, differs little from the ramshackle set of a spaghetti western. On horseback, my guide and I clopped through the oasis town, along burbling channels, past adobe houses and verdant orchards. Into the desert we rode, to the Valle de la Luna, labouring up vast sand dunes to survey the lunar rock formations below. At 2,450 metres, the light was eerily intense, the sun bathing the volcanic cones of the Andes in the most impossible red.

At dawn we negotiated the steep climb to the famous Tatio geysers. We drove through a desert of gravel and rock, landscape changing at every bend, the smoking hulk of Volcan Putana the only constant in our sights. At 4,300 metres we reached a plateau of some 40 geysers. Magma-boiled underground streams met the cold morning air, sending up hissing plumes of sulphur-scented steam. Delicate vicuñas grazed, and backpackers soaked in bubbling pools, like steaming dumplings.

Dusk came over the Salar de Atacama, its surface jagged and sand-dusted like a ploughed field. This salt lake harbours almost half the world’s lithium – used to pep batteries and to spark the neurotransmitters of the depressed.

Mario arrived to take me to Bolivia. “It’ll be different,” he muttered. The frontier at San Pedro was decorated with “wanted” posters of moustachioed Bolivians. Since 1879, when Bolivia lost her coastline to Chile, little love has been lost between these countries. We sped through a no man’s land flanked by minefields, took a dirt track and rose past Licancabur to a shack flying the red-yellow-green tricolor: Bolivia. Within 100 kilometres we had climbed to 4,850 metres.

It was literally breathtaking, like Chile on LSD. It was not just that beautiful Red Lagoon, where flamingos join the llamas to set the lake aflutter. There is also a Green Lagoon – a milky, viscous jade so rich in lead and arsenic that no sensible creature approaches.

In Bolivia, the Sol de Mañana geysers do not hiss suggestively: they roar deafeningly, through yawning craters. Mud gurgled hungrily at 600C. The breath of the devil hung in the air.

That evening, dining on llama fillets at the only joint in town, among miners on a karaoke outing, I understood what Mario meant by “different”. We checked into the Luna Salada, a hotel sculpted entirely of salt, overlooking the world’s largest and highest salt lake: the Salar de Uyuni. Unlike the Chilean version, it stretches flat over 12,000 square kilometres of hexagonal patchwork, snow-blindingly white. We raced across it, glad of a smooth surface. Though sunny, it was bitterly cold. Giant cacti teetered on rocky islets, adding to the sensory confusion.

On arrival at an Inca burial cave, full of foetal-position mummies waiting to be reborn, I thought the altitude must be affecting me. It was. “Coca leaves,” suggested Mario, when orthodox remedies failed. “They aid oxygen uptake.” Leaves were produced.

I was shown how to prepare then store them in a mulch in my cheek. My throbbing head responded, enabling us to climb to Potosi: once the richest, still the highest, and one of the most affecting cities in the world.

Potosi is where the New World encountered Spain at her least likable. Cerro Rico, source of Spain’s riches for 300 years, towers drably above this tiny city of narrow streets, overhanging balconies and churches whose baroque curlicues are out-flourished by the exotic motifs of mestizo culture. Indians were fed into the Cerro’s mines to extract silver to be transformed into Spanish coins. Astonishingly, the 360 mines still functioning are almost unchanged.

Armed with the novel gift of dynamite from the miners’ market, we visited one underground labyrinth. A cross stood above the entrance, decorated with flowers. For good measure it was splashed red with the blood of a llama: a sacrifice to the earth mother, Pachamama. Sporting headlamps, we crouched in the gloom. It was stifling and disorienting. It reeked of fumes from explosions. We followed the din of pneumatic drills to find two miners hoisting themselves from a pit, blackened but smiling. We proffered our dynamite, then retired to sup with an effigy of the devil. Someone placed a lighted cigarette in Old Nick’s mouth, a bottle of alcohol in his lap. Miners will hedge their bets with any deity to hand.

In Sucre – the judiciary capital, with all the whitewashed, colonial elegance and Catholic pomp of its heyday – I walked over cows’ bones arranged in cruciform pattern, “to exorcise the ghosts of Spaniards killed in duels”. In La Paz, not only Indian women in colourful shawls and bowler hats seek advice from hechiceros in the Witches’ Market. The bourgeoisie also gather, selecting llama foetuses, condor plumes, stuffed owls and assorted herbs for hexing and veneration. “Believe in God or not,” explained Mario. “But deny Pachamama and all work stops.” This the Americans discovered. Their new embassy is founded on the remains of a llama.

I met my own doctor-magus, a kallawaya, on my final evening, on the tranquil shores of Lake Titicaca. Benjamin read my fortune using sacred coca leaves. Charily, I sat as he invoked the spirits of the Andes, Pachamama and St James, and blessed, then hurled, alcohol into the fire. The flames billowed, auguring well. The leaves fell auspiciously. I celebrated with local trout, Bolivian wine and a coca-leaf massage. It seemed a fitting end to a journey through magical realms.

HOW TO GET THERE

Teresa Levonian Cole travelled with Cox & Kings - a 16-day/13-night tour of Chile and Bolivia starts at £2,895

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