It's been described as the closest humans can get to heaven on Earth. With its ethereal and richly contrasting landscapes, small permanent population and ever-growing economic potential, the Salar de Uyuni has all the elements of a fantasy novel. And to add to the mystique, almost 40,000 years after its formation, there's still contention about how and why it exists.

Located in the south-west of Bolivia, the Salar is the world's largest salt flat and one of the most curious natural phenomena in South America. Scientists have vaguely narrowed its origin down to the evaporation of prehistoric lakes, but concede some of its potential – and history – is only just being discovered.

For good reason, the remote landscapes attract thousands of tourists each year and few go home disappointed, particularly if they manage to capture any of the Salar's five most captivating sights.

1. WHERE EARTH & SKY MEET

What you're looking at: Salar de Uyuni is a lake the size of Hawaii's Big Island that thickened and dried out over thousands of years, leaving a mass of brine and a crusty 10 billion tonne layer of salt. In winter, a thin layer of water covers the lake, giving it a reflective appearance, but it can still be driven over in an all-terrain vehicle. The surface is rich in lithium, which is mined for batteries and electrical goods, but as far as tourists are concerned, it provides spectacular optical illusions.

Why it's a must-see: There is no natural formation, on this planet at least, quite like the Salar. It's full of geological marvels, like cracked hexagons of salty ground, mirror-like surfaces where the lake and sea meet in the rainy season and volcanic backdrops. It's popular among photography enthusiasts because the landscape takes away perspective, which means a person can stand a few metres away from a tuna tin and appear to be the same size.

Similarities? The lake has been compared to the surface of the moon and a giant mirror. The salt also has a snow-like appearance.

2. PYRAMIDS OF SALT

What you're looking at: Massive piles of salt are a common sight across the arid Salar. Miners stack them up to drain moisture from the grains before piling the mounds on a truck for processing.

Why it's a must-see: Amid the natural wonders, this is one of the few continually changing human contributions you'll see. But it doesn't look like something created by the hand of man. The well-formed pyramids are particularly special because they look like they've pierced the surface of the ground and are growing from the watery surface. It's another surreal encounter that makes for an unusual photo album entry.

Similarities? Picture a miniature Giza, but less rigid in structure and often blindingly white.

3. A RAIL GRAVEYARD

What you're looking at: The detritus of 19th century trains provides perhaps the starkest contrast to the rest of the region's natural charm. In the battle between nature and man, nature won out here with these British locomotives falling into disrepair in the 1940s when a mineral train line was no longer seen as viable.

Why it's a must-see: Which other major tourist attraction would consist of 30 or so corroding trains in the middle of a desert? If nothing else, it's a bizarre sight, and unlike most wrecks, travellers are actually allowed to climb inside these carriages, making it a favourite spot for kids and trainspotters alike.

Similarities? It's a bit like Healey Mills Traction Depot in West Yorkshire, UK, but bigger and older.

4. CACTI ON INCAHUASI ISLAND

What you're looking at: In the very centre of the Salar lies Incahuasi Island, a 25 hectare (think 25 football fields), cacti-covered rock formation, which is sometimes referred to as Fish Island.

Why it's a must-see: While not as picturesque as the lake or pyramids, the sheer strangeness of the brimming cacti is worth seeing. The tallest cactus on the island, which is estimated to have been living for more 900 years, is more than 12 metres high. Travellers are offered the opportunity for perspective pictures of another sort – at the top of the rocks, photographers can snap the meeting of desert and coast. On a clear day, it's hard to differentiate the two.

Similarities? A number of countries across South America, including Argentina, Chile and Peru, have high cacti populations, but rarely this close to the coastline.

5. PINK FLAMINGOS

What you're looking at: A native population of flamingos, Andean geese and hillstars are among the 80 bird species that can be found in the Salar. It's also worth keeping an eye out for the culpeo, a fox-like creature that preys on birds and rodents.

Why it's a must-see: Apart from the landscape, one of the more talked about and spectacular sights in Uyuni is the pink flamingos, who use the Salar as a breeding ground. Against the dry backdrop, the majestic creatures – who gain their colour from feeding on red algae – provide a memorable sight. The sea of colour is particularly striking after days of seeing only white and earthy hues.

Similarities? Think Lake Nakuru in Kenya, where hundreds of flamingos gather frequently to feed on the abundant algae.