As celebrations take place in Nepal to mark the fiftieth anniversary of the first ascent of Everest, strong connections between the expedition and Wales have emerged.
The view from the top of the world
The highest point in the world was named after the Victorian geographer Sir George Everest.
Born in Crickhowell, Breconshire, in 1790, Sir George later became surveyor general of India.
His job entailed making and commissioning maps and he was the first British authority to report on the existence of the mountain.
It was his work on refining and perfecting trigonometrical equipment that enabled an accurate measurement of its height.
That won the Welshman the honour of having the peak named after him.
It was in the mountains of Snowdonia that the successful British expedition under Sir John Hunt trained in 1952, testing out the tactics and equipment that led to the climbing of Everest by Sir Edmund Hillary and Sherpa Tenzing Norgay the following year.
My father got all the guests out of bed and told them if they did not get up they would be thrown out
Jane Pullee on the day Everest was first climbed
Midnight phone call
Pen-y-gwryd Hotel in Nantgwynant was the social centre and meeting place for six months for the expedition, and next month the surviving members will meet for a reunion, as they have done regularly since 1953.
The hotel was a mecca for climbers and the owners were Chris and Jo Briggs and their daughter Jane, then aged only 10.
Sign of the times: Everest now has an internet cafe
She remembers a phone call at midnight on 1 June, 1953.
"It was from The Times, telling my parents that the expedition had done it," she said.
"My father got all the guests out of bed and told them if they did not get up they would be thrown out."
That morning, the guests were treated to a champagne celebration.
Today, the walls of the hotel are lined with memorabilia of the expedition and Jane, now Mrs Pullee, treasures the picture of her taken with expedition leader Sir John Hunt.
She said: "Those involved in the expedition became a family and my parents really were part of the Everest family."
The Welsh connection continues with Charles Evans, a surgeon from the Vale of Clwyd who later became the head of the University of Wales, Bangor, and lived in Capel Curig.
Caradog Jones was the first Welshman to make it up Everest
He could have been the first to reach the top of Everest as the lead climber of the expedition. He and climbing partner Tom Bourdillon set out on the first attempt to reach the summit on 27 May, but they had trouble with their oxygen equipment and had to turn back, just 300 feet short.
So, fate stopped a Welsh foot being the first on the top, and two days later it was Hillary and Tenzing who made the successful ascent.
You can see the curvature of the earth at that altitude, so it's definitely a somewhat surreal experience
Mrs Pullee will be at the official celebrations in London on Thursday, culminating at an evening royal gala, at the Odeon Cinema, Leicester Square.
There will also be an afternoon event featuring film and speakers on Everest...and yet another Welsh connection.
One of the speakers will be Welsh author Jan Morris, who was The Times correspondent with the expedition and was the first to get back the news to the world.
She will be making the trip from her home in Gwynedd to take part.
It was one of the classic newspaper scoops, reaching Britain on the day of the Queen's coronation.
Welshman on top of the world: Caradog Jones in 1995
Fewer than 50 Britons have made the summit, and the first Welshman to get there was Caradog Jones in 1995.
He said his team had been under a lot of pressure to persuade those below that they had the strength to carry on.
Mr Jones told BBC Wales: "You're actually climbing out of the protective layer of the atmosphere.
"You have this feeling of a great thickness above you when you're at home, but you suddenly realise that you've climbed out of it.
"You can see the curvature of the earth at that altitude, so it's definitely a somewhat surreal experience."
Another Welshman, Eric Jones has been up Everest twice as a cameraman, but never to the summit.
But he had frostbite and he said he had not thought it was worth the risk of losing his fingers to get to the top.
Mr Jones said he objected to the number of inexperienced climbers who were now going up the mountain on commercial expeditions.
"It's all down to money," said Mr Jones. "The Nepalese and Chinese government get vast amounts of money from these expeditions, so I'm afraid they are just going to take as many as they get.
"But the problem is there are so many inexperienced climbers on Everest and if they are caught high up in a storm they are likely to die."