The Duke and Duchess of Cambridge were left marvelling at Uluru at sunset after spending the day in the Australian outback.

William and Kate watched as the landmark sandstone outcrop - also known as Ayers Rock - changed colour before their eyes from a luminous red to a deep purple as the sun dipped below the horizon.

Ahead of their visit to the site, revered by local Aborigines, the Duchess described it as "absolutely stunning" after seeing it from the air while landing at a local airport.

The couple were able to spend more than an hour visiting Uluru before watching the magical sunset.

William and Kate's day in the heart of Australia saw them meet indigenous people from across the country when they visited a training academy aiming to put Aboriginal workers front and centre in the tourism industry.

And they received a traditional welcome from elders from a local community - and a souvenir spear.

Before enjoying the sunset, the Duke and Duchess posed for photographs with Uluru in the background, just like any other tourist couple - but it was the world's media taking the pictures.

After the cameras were put away, William said to Kate: "I actually thought the sun was going to be behind us for some reason, but it's the other way around."

A school girl, who was lucky enough to witness the photo opportunity, joked about the flies that plague anything that moves.

She said: "You were both like magic when the photos were being taken. I was like 'How are they not swatting flies away?'."

Kate laughed: "I know. It was difficult", while William added: "They were all coming for us."

Uluru was named Ayers Rock in 1873 by surveyor and explorer William Gosse in honour of the then chief secretary of South Australia, Sir Henry Ayers.

The sandstone rock, which rises 1,142ft (348m) above the red earth around it and has a circumference of 5.8 miles (9.3km), was formed over hundreds of millions of years when sand was deposited on the bed of an inland sea.

The seabed was compressed into rock and then turned through almost 90 degrees by the shifting of tectonic plates, meaning the layering of the sandstone of Uluru is almost vertical today.

Over hundreds of millions of years, a mountain range that surrounded Uluru was eroded away, leaving the unusually hard sandstone monolith exposed.

Its red colour comes from the oxidisation of iron-bearing minerals within the rock through exposure to air and water. Below the surface, the rock is grey in colour.

William summed up his feelings about Uluru when he told Kate: "It's a beautiful sight though. Quite breath-taking."

Kate changed out of a Roksanda Ilincic dress she wore earlier into a patterned one from high street chain Hobbs for the visit to the landmark.

Earlier, the royal couple enjoyed a rare moment of solitude when they visited a water hole at the bottom of Uluru.

They strolled alone to the secluded spot along the Kuniya walk and were rewarded by the magical sight of a pool of black water surrounded by weathered and sweeping walls of sandstone towering above them.

Tour guide John Sweeney, who accompanied the Duke and Duchess's Aboriginal guide, Sammy Wilson, said: "We let them have a bit of time to themselves, which is pretty rare on a trip like this."

William said: "It is nice and peaceful there - a beautiful spot. It is special."

When the guides re-joined William and Kate, they pointed to two important ancestral beings surrounding the waterhole, Kuniya - the python woman - and Liru - the poisonous snake man - who was hit over the head with a stick by Kuniya to avenge the wounding of her offspring.

Kate chuckled when she read the information on the boards close to the water.

After the couple's brief private moment, the group walked to a small cave, where they viewed Aboriginal artwork painted on to the base of Uluru.

Mr Wilson was well placed to explain its significance to the local Aboriginal settlement of Mutitjulu as his grandfather was the artist.

Mr Sweeney said: "Sammy told them the ancestral story, which relates to how this part of Uluru was formed.

"Sammy showed the cave paintings that his grandfather did, which was one of the last paintings done at Uluru.

"They were very interested in everything that was said. They were an absolute pleasure. They were very inquisitive. They said the rock was very impressive."

Earlier, in a welcome ceremony at a cultural centre in the shadow of Uluru, William and Kate watched as two senior Aboriginal women and a senior man danced and acted out the stories of creation and their ancestors.

The royal visitors, who sat in the shade to escape the stifling heat, were also presented with gifts.

Kate was given a necklace made from natural elements found in the desert -painted gumnuts and rich red ininti seeds.

As the main performance ended, William stood to be given a paddle-shaped hand-made shield called a tjara.

The shield has an ancient history as a defence against spears and clubs.

Before touring Uluru, the couple visited the National Indigenous Training Academy to present recent hospitality and catering graduates with their certificates.

They then went on a brief walkabout, meeting well-wishers who had gathered in the grounds of the academy.

Kate chatted to Amanda Bartels, 30, who had driven for five hours from Alice Springs to see the royal visitors.

Speaking about Uluru, Kate told Ms Bartels, who was holding her 10-month-old son Nathan: "It's absolutely stunning from the air."

The 30-year-old mother, who also brought her five-year-old daughter Aimee-Grace to see Kate, said after meeting the Duchess: "I asked her if she was missing George and she said she was so I said my son could be her George substitute.'

"She let him play with her bracelet and she said 'You like that, do you want it?'.''

During the visit, William was presented with a spear by husband and wife indigenous couple Kamurin and Sherelle Young, who are students at the academy and hope to become managers in hotels.

The royal couple marvelled at the long weapon made from local wood and carved to a sharp point.

Mrs Young said afterwards: "William was pleased, he was so thankful. I told him it was made from wood from the Mulga tree and that it had kangaroo vein, used as twine, on it he was shocked he said 'Wow'."