"I cannot believe what I saw up there." The harsh reality of climbing Mount Everest.

When the mind thinks of Mount Everest, the world’s tallest mountain, it likely conjures up images of jagged peaks covered in snow, with one or two brave adventurers who have climbed for months to conquer it.

Maybe it imagines the inhospitable conditions; strong, freezing winds or a deadly avalanche.

What it’s unlikely to think of is a traffic jam of brightly coloured backpacks and puffer jackets, as more than 100 climbers queue to reach the summit.

But that is what awaited those who reached Everest’s summit last week, as a photo by mountaineer Nirmal Purja captured on Wednesday.

#ProjectPossible update. I summited Everest at 0530 and Lhotse at 1545 despite heavy traffic. I am now at Makalu base camp. Will be going directly for summit push from base camp. I will update once Makalu is complete. Thank you for my support especially my sponsors. pic.twitter.com/mAiLTryEln

— Nimsdai (@nimsdai) May 23, 2019

Queues to reach the top of Everest can take hours, as the time that climbers can safely reach the peak is often only a small window of two or three days.

Posting to Facebook, adventure filmmaker Elia Saikaly shared a photo of himself at the summit, adding he “cannot believe what I saw up there”.

“Death. Carnage. Chaos. Lineups. Dead bodies on the route and in tents at camp 4. People who I tried to turn back who ended up dying. People being dragged down. Walking over bodies,” he wrote.

“Everything you read in the sensational headlines all played out on our summit night.”

He also shared a disturbing photograph of climbers stepping over a dead body.

“This poor human being perched 7000ft above the Western CWM for everyone to observe was a reminder of each of our own mortality. Was this the ‘Dream of Everest’ we all imagined?” he wrote.

The death zone.

On Mount Everest, long queues can be deadly.

There have been 10 deaths in two months as a record number of climbers rush to conquer Everest, with this year’s weather providing only five days of conditions safe enough to summit. At least two climbers died after reaching the summit last Wednesday, the same day Purja captured his photo, and the delays may have contributed.

The congestion means climbers are spending longer than advised above 8000 metres, in Everest’s ‘death zone’, where oxygen levels are only a third of what they are at sea level. The longer a person spends at high altitudes with low air pressure and oxygen, the higher their risk for altitude sickness.

 

View this post on Instagram

 

A post shared by Nirmal Purja MBE – Nims (@nimsdai) on Mar 25, 2019 at 2:40am PDT

Everest is the world’s largest open-air graveyard, littered with the bodies of those who have died while climbing it. Many bodies – most of which are in the death zone – have become markers for others attempting the climb.

Weather conditions, terrain and low oxygen levels make retrieving bodies on Everest near-impossible – and even if you’re willing to try, an expedition to recover remains from the death zone can cost more than AU$110,000.

If bodies are found, they are usually stuck to the mountain, frozen in place for good.

Green Boots.

Perhaps Everest’s most infamous marker is Green Boots, the frozen body of a fallen climber who earned his moniker because of his brightly coloured hiking boots.

Green Boots’ identity is widely believed to be Indian climber Tsewang Paljor, who lost his life in a 1996 blizzard after reaching the summit with two others.

The fourth member of their expedition, Harbhajan Singh, had urged the three men to abandon their attempt to summit due to incoming bad weather, but they persisted.

“Don’t be overconfident,” Singh insisted. “Listen to me. Please come down. The sun is going to set,” he told the men via walkie-talkie after abandoning his own attempt and descending back to camp.

Over time, Paljor became known as Green Boots and was a permanent fixture on the North Col passage, his body curled in a limestone alcove cave at 8500 m. His legs sprawled across the path, so everyone who passed needed to walk over them – a harsh reminder of the mountain’s brutality.

In 2014, climbers noticed that Green Boots had disappeared, but in 2017 several climbers believed he had once again become visible and was covered in stone.

Sleeping Beauty.

In 1998, Francys Arsentiev became the first woman from the United States to reach the summit of Mount Everest without the aid of bottled oxygen, but she and her husband Sergei never made it back down.

The pair reached the summit late in the day and were forced to spend another night above 8000m. During the night, Francys and Sergei became separated.

Sergei made his way down to camp, assuming that his wife had done the same. When he discovered her absence, he raced back up the mountain with oxygen and medicine, hoping to rescue her.

Accounts vary, but on May 23 an Uzbek team found Francys half-alive and unable to move without assistance. They carried her down as far as they could before their own oxygen ran out and they were forced to leave her and descend to camp. On their way down, they passed Sergei on his way up to her. He was never seen alive again and his body was not found until much later.

For nine years, climbers scaled around Francys, who became known as 'Sleeping Beauty', before her body was dropped to a lower location on the mountain face, out of view.

David Sharp.

In 2006, Green Boots' cave became even more infamous when British solo climber David Sharp was discovered huddled inside, barely alive.

He had successfully summited Everest on his third try and, during his descent, stopped to rest inside Green Boots' cave, just feet from Green Boots himself.

Sharp drew his legs to his chest and rested his head upon his knees. At the time, media widely reported that Sharp moaned and murmured as around 40 climbers passed him without offering any aid. He died later that day, alongside Green Boots.

Sharp's death caused major controversy within the climbing community, with Sir Edmund Hillary - the first person to ever successfully summit Mount Everest - detesting the attitudes of climbers as "horrifying".

"A human life is far more important than just getting to the top of a mountain," he told the New Zealand Herald.

A year later, Sharp's body was removed from sight at the request of his parents.

Melting ice means... more bodies.

More than 300 people have died on Mount Everest, and the vast majority still remain there.

While the remains are perfectly preserved in the mountain's freezing temperatures, warming temperatures attributed to climate change are exposing bodies that had been covered in ice and snow for decades.

"Because of global warming, the ice sheet and glaciers are fast melting and the dead bodies that remained buried all these years are now becoming exposed," Ang Tshering Sherpa, former president of Nepal Mountaineering Association, told BBC News in March.

"We have noticed that the ice level at and around the base camp has been going down, and that is why the bodies are becoming exposed."