Mumbling enthusiastically in Spanish, Santos Quispe Cayo, a 68-year-old quinoa farmer, directs me to a collection of large pre-Colombian clay pots lined up in the corner of his parched, sun-beaten garden.

The simple pieces of earthenware, which could be anywhere between 800 and 1,200 years old, form part of a bizarre collection of historical oddities dug up by self-made archaeologist Santos, from fields at the foothills of Bolivia's Mount Tanupa.

His star exhibit though, lies at the bottom of a macabre sculpture garden, where lama bones and volcanic rocks have been used to assemble crude pieces of art. In a small cave sits a crouched skeleton, with a few rags still clinging to its bones. It's most probably an indigenous Aymara who walked on this soil eight centuries previously, he casually tells me, just one of "many mummies you can find here".

Were it not for a faded and curled certificate vouching for the museum's authenticity, I'd be in complete disbelief. But in a country where the government appears to show little interest in restoring the past for future gain, it's all very plausible.

Hindered by ongoing industrial disputes and a controversial socialist administration, Bolivia has always been the poor child of South America, rich in natural resources but failing to attract the tourist numbers of neighbouring Peru. Yet its overwhelmingly diverse scenery and largely unexplored archaeological sites evoke a sense of real discovery for anyone who visits.

I'd arrived in Bolivia several days earlier, crossing the border from Chile at Hijo Canjon, with a local knowledgeable driver. Turning onto a bumpy dirt track, I waved goodbye to paved tarmac and road signs for the next seven days, embarking on a journey that would take me through the Andes and Bolivia's Altiplano, climbing to head-thumping heights of 5,000m.

Leaving clouds of dust in our wake, we pass volcanic cones streaked with a rainbow of mineral deposits on our way to the Eduardo Avaroa Andean Fauna National Reserve.

At midday, we stop at Laguna Verde and wait for the sun's warmth to turn the arsenic-rich water turquoise, like ink seeping through litmus paper; then continue to the algae-rich, blood red Laguna Colorada, where swirling pink flocks of James's flamingoes appear incongruous in a far from tropical environment.

As the air thins and my breath shortens, we reach the 4,800m Sol de Manana geyser field, where vast pools of viscous mud aggressively bubble and jets of steam soar into the sky.

It's hard to imagine anything could live here, but as we drive through a narrow canyon, small viscacha twitch their whiskers between crevices, and vicuna (wild camelids) dart across the horizon.

Our resting place is the area's only decent hotel, Tayka del Desierto, powered by a simple generator and exposed to a raging wind responsible for sculpting a Daliesque landscape of rocks hewn into petrified trees and other surreal shapes.

Undoubtedly Bolivia's greatest tourist attraction is the Salar de Uyuni, the world's largest salt flat, pulled taut like a blinding white blank canvas across a 12,000sqkm frame.

Formed from prehistoric lakes, the honeycomb patchwork of crystallized crust is also a cause of concern for environmentalists, as a rich source of lithium lies beneath its surface, a prospect too tempting for the government to ignore.

Having stayed the night at Palacio del Sal, a hotel carved entirely from salt, we drive to Incahuasi, one of many island oases dotted across the flats, and climb a path weaving through tall, bulbous cacti.

Our journey continues for several more hours before salt gives way to soil at the foot of Mount Tanupa, where llamas graze in the shadow of Santos Quispe Cayo's sculpture garden.

During high season (May to October), dozens of vehicles converge in the salt flats, but as we leave the Museo de Chantani and continue our journey through the Altiplano, we barely see a soul.

There are only 11 million people living in Bolivia, a country the size of California and Texas combined, but with a sixth of the population. In the last five years, conditions have improved greatly for working classes in the countryside, mainly as a result of a growing market value for grain of the Gods quinoa, and it's not uncommon to see gleaming Toyotas parked next to simple adobe brick houses half their size.

Many of the country's hotels are also community run - to varying degrees of success - as a result of President Evo Morales' reluctance to allow foreign investment in tourism. One flourishing business is the Tomarapi Ecolodge in the Sajama National Park, where guests stay in simple lodges and homemade food is cooked in an outdoor clay oven.

The park's main attraction is the 6,542m Sajama volcano, the second highest peak in South America, but we choose to tackle less arduous walking trails during our stay.

Passing a bofedal, where camelids gather to graze and drink water, we trek through bristly teardrops of bunched hard grass and yareta plants that bear a disturbing resemblance to neon cowpats, until we reach a patch of khenua bushes, constituting the highest forest in the world.

Five communities still live inside the national park, and we encounter families using volcanic stones to build barbecues, and cholitas (indigenous women in traditional dress) boiling eggs in the hot springs of geyser fields.

But even in big cities such as La Paz, it's possible to find cholitas wearing bowler hats and a millefeuille of petticoats, as we discover when we visit.

Cradled in the Cordillera mountain range at an elevation of 3,650m, Bolivia's administrative capital straddles worlds past and present. At one end of town, gourmets dine in boutique restaurant Gusto, run by the team behind Copenhagen's famous Noma, while downtown, Witches' Market apothecaries still sell dried lama fetuses and a myriad of potions.

As we ride in a new government-funded cable car above the city, I look down and see a guitar-strumming minstrel singing to tombs in the city's main cemetery, an extremely moving practice that's been undertaken for years. Although of great benefit to the local community, I do wonder if the large amount of money spent on the Teleferico project could have been better invested elsewhere - namely in excavating some of the country's largely unexplored archaeological sites.

The most famous to date is Tiwanaku, just outside La Paz, a pre-Colombian city thought to be twice the size of Machu Picchu and thousands of years older.

Despite being exposed to the sun and wind, the sunken floor of a grand temple is remarkably well preserved, featuring a series of unnerving sandstone faces, which some scholars theorize were created to reflect the different cultures passing through the community at that time.

During my visit, I count just four people excavating the still largely uncovered site, and I wonder, at this rate, how many years it will take for Bolivia to discover it's truly inexhaustible resource.

For now though, until the correct funding is in place, perhaps it's safer it remains underground.

TRAVEL FACTS

:: Sarah Marshall was a guest of HighLives Travel (www.highlives.co.uk; 020 8144 2629) who offers the 13-day Bolivian Odyssey from £2,100 per person - excluding flights. Extension to Sajama National Park costs from £600 per person. Tour includes accommodation, transfers, guided tours and some meals.