Machu Picchu, the 15th century Inca citadel, has become a cornerstone of Latin America tourism since the American historian, Hiram Bingham, first stubbed his toe on an overgrowth-covered stone slab in 1911.
Today the site attracts up to 700,000 visitors each year: in the forthcoming high season (July and August) you can spot around 1,000 Gore-Tex jackets clambering over the Sun Gate to catch the first rays at dawn.
In recent years, however, concerns have been expressed that Machu Picchu is falling victim to its own success. The primary concern is that the high volume of visitors is harming the site's infrastructure. The United Nations cultural agency wants visitor numbers more than halved, while Unesco has said that it may put the ruin on its list of endangered sites.
A couple of years ago, a survey by Japanese geologists from the Disaster Prevention Research Institute at the Kyoto University suggested the earth beneath the 2,250m-high city is moving at a rate of up to one centimetre per month.
The National Cultural Institute of Peru - the managing body responsible for Machu Picchu - have responded with a slew of measures intended to limit tourist numbers and improve conditions for the porters, who carry travellers' backpacks in all weathers along the high-altitude Inca Trail. As a result, most visitors must now wait four to five days in Cuzco before getting a place on a trek.
Despite this, Machu Picchu remains the number one must-see in South America. And, as such, the hunt is now on for new Inca ruins as a viable, ecologically sound alternative.
What most people don't realise, however, is that there's no shortage of alternative Inca trails, including hikes in Bolivia and Ecuador, Peru's Andean neighbours.
The 14,291mile Inca road network is the largest contiguous, prehistoric archaeological structure in the Americas - built over 500 years ago, it connected the various subject peoples of the Inca Empire with a central authority in Cuzco. Even today the route is scattered with ancient Inca sites, many of which are still relatively unexplored by tourists.
"I think the problem is that travellers don't respect the Inca trail or the culture it represents," says Efrain Condori of United Mice, one of the best-regarded, Cuzco-based trekking specialists.
"But, given Machu Picchu's global reputation, I think it will take a lot of time and investment in infrastructure before we see any major movement away from Machu Picchu in favour of lesser-known Inca sites."
Here we present four alternatives to Machu Picchu where you can catch the ruins but avoid the crowds.
The Choquequirao trail, Peru
Where? Meaning "Cradle of Gold" in the local Quechua language, this site - located just 50 miles from the world-renowned Inca trail - is being hotly tipped as the next Machu Picchu.
What's to see? The new site is currently being championed by a French government initiative personally overseen by President Chirac. While the site is open for visitors, excavations are continuing to uncover the ruins. With new EU funding incoming, the development of surrounding infrastructure is likely to continue apace in the next few years.
How to get there: From Cuzco, it's a tough eight-day trek by mule along passes in the Vilcabamba mountain range at an altitude of up to 4,600m - not for the faint-hearted.
The package: Steppes Latin America (01285 885333; steppeslatinamerica.co.uk) has a 14-day tour, leaving on July 31 and October 16, for £2,145 per person, including international flights and taxes.
The Ingapirca trail, Ecuador
Where? Ingapirca, located just 31 miles north Cuenca, is one of the most significant sites of the Inca empire and Ecuador's best-preserved Inca ruins.
What's to see? Following Inca pathways past mountain lakes and grassy valleys, this is one for scenery lovers. Better still, chances are you'll have the trail to yourself as it receives just a fraction of the foot traffic of other Inca routes. Afterwards, stop off in the colonial city of Cuenca, the home of the Panama hat.
How to get there: Head by road from Quito to the trailhead at the village of Achupallas, after which it's a moderate three-day trek. The last section of the trail is follows a 7m-wide Inca road directly to the ruins at Ingapirca.
The package: Tribes (01728 685971; tribes.co.uk) offers a tailor-made trip year round from £630 per person, excluding international flights, based on two people sharing.
The Choro trail, Bolivia
Where? Descending steeply from a high-altitude (4,750m) pass at La Cumbre, 14 miles outside of La Paz, to low-lying Coroico in the tropical Yungas region, this is one of the most popular treks in Bolivia.
What's to see? This well-signposted trail follows a pre-Hispanic road that cuts through a savage but spectacular landscape via tiny villages and rustic pueblos. It's low on infrastructure - take plenty of supplies - but great for a glimpse of rural Bolivian life. There's also an overnight at the orchid plantation of Sandillani.
How to get there: Accessed from La Paz, it's a moderate four-day, 37 miles walk and, best of all, almost completely downhill.
The package: Andean Trails (0131 467 7086; andeantrails.co.uk) has a four-day trek, plus bus transport back to La Paz, for £250 per person, based on two people trekking. Price includes bilingual trekking guide, all meals, camping equipment and park fees.
The pre-Inca trail, Peru
Where? From Cajamarca, inland from Peru's northern coast, the trail leads, via Chiclayo and Sipán, where the most elaborate Moche tombs in Peru were discovered in 1987, to the town of coastal town of Trujillo, visiting other pre-Inca sites at Pampa Grande, El Dragón, and Chan Chán en route.
What's to see? There's more to Peru than just the Incas. Indeed, the north coast of Peru was home to the pre-Inca civilisations of the Moche and Chimu cultures, whose handiwork with roads and canals are thought to have inspired the Inca's vast network.
How to get there: Cajamarca has daily flight connections to Lima; some flights are routed via Trujillo.
The package: Journey Latin America (020 8747 8315, or 0161 832 1441 for JLA Manchester; journeylatinamerica.co.uk) can arrange tailor-made trips to the region. They also offer an add-on, eight-day itinerary to Cajamarca for £1,453 per person on a B&B basis, including flights to Lima on KLM and surface transport.
More information:
The Latin America Travel Association (LATA: 020 8715 2913; lata.org) produces a free guide to travelling in Latin America.
The South American Explorer's Club (saexplorers.org) offers advice on treks from their clubhouses located in Quito, Lima and Cuzco.
For more on Bolivia, try Magic of Bolivia (020 8378 9194; bolivia.co.uk), the UK's specialist Bolivia tour operator with both group and tailor-made excursions.
For Peru, Prom Peru (peru.org.pe) is the national tourist body, with advice on new Inca sites.
For Ecuador, try the independently-run ecuadorexplorer.com.
For more about general travel in Latin America, see David Atkinson's website: intrepidtravel.com/Atkinson
Further reading:
Bolivia Handbook (Footprint, £14.99)
Lonely Planet Bolivia (Lonely Planet, £15.99)
Peru & Bolivia: The Bradt Trekking Guide (Bradt, £12.95)
