The BBC is celebrating the 1953 British Everest expedition, the first to reach the mountain's summit. BBC correspondent Jane Hughes, who is at base camp, is keeping a diary of her experiences.
Day 21: A day to remember
Everest: The greatest peak
Finally, the date we have been anticipating for so long - 29 May, the 50th anniversary of Sir Edmund Hillary and Tenzing Norgay's historic climb to the top of the world.
Here at base camp, the day dawned gloriously bright, with the panorama of mountains shimmering in the morning sunshine.
Our first thought is with the climbers up on the mountain hoping to follow in the footsteps of Hillary and Tenzing exactly half a century on. But although it is blissfully warm down here, up above 8,000 metres it is blowing relentlessly, as it has for so much of this climbing season.
The mountaineers up at camp four on the south col radioed down to say the wind was so strong they could hardly stand up outside their tents, let alone consider ascending to the summit.
Their bid has been postponed for 24 hours. So, on the 50th anniversary of the day the first two men stood on top of Everest, the great mountain's summit will be deserted.
Sardines and biscuits
Edmund Hillary and Tenzing Norgay had much better luck with the weather.
They awoke high on the mountain to find the temperature in their tent was minus 27 Celsius - but the wind had dropped and the night was very still.
They could see the peaks below them glowing in the early morning light.
Hillary's boots had frozen and he had to heat them over his primus stove to thaw them out.
1953 EVEREST EXPEDITION
Everest formed 60 million years ago
Rising 4-10 cm a year
Called Sagarmatha in Nepal
Down to -72C at top
1,300 people have reached summit
They ate a rather unappetising-sounding meal of tinned sardines and biscuits and then set out for the top.
They reached the south summit by 9 o'clock in the morning and then pressed on into uncharted territory, higher than anyone had ever been before.
The toughest challenge they came upon was a face of rock which has since been called the Hillary Step. Looking down one side of the ridge was Tibet thousands of metres below; looking the other way, Nepal lay before them.
After they had wriggled their way up the step and walked a little further, suddenly they stood on top of the world.
Hillary said that despite his oxygen mask, balaclava and goggles, there was no disguising Tenzing's infectious grin of pure delight.
He took a quick photo of Tenzing and of the mountains below and then they headed back down, exhausted.
When they made it to their companions further down the mountain, Hillary uttered the immortal words, "Well, we knocked the bastard off".
Our thoughts today have been very much on that extraordinarily brave achievement.
Climbing Everest now on well-worn routes is enough of a challenge; Hillary and Tenzing were ascending into the complete unknown.
Hillary: He led the way
There aren't many people left in base camp to reflect on what they did.
Most have already gone down the mountain to the big celebrations taking place further down the valley.
But as we end our journey up to 5,000 metres, in memory of Hillary and Tenzing's success, and as we look up at the formidable peak they conquered, this feels like the right place to be.