Nearly 1,800 people have conquered the world's highest peak at 8,850 metres since Hillary and his Nepali climbing mate Tenzing Norgay Sherpa made their historic ascent in 1953.

Over the years, the slopes have become a dumping ground with mountaineers leaving behind tonnes of supplies, climbing gear, oxygen bottles, gas cans, batteries and ropes.

Nepali and foreign climbers have removed some of the garbage in recent years, but Hillary said it was not enough.

“It is very important for the people on the mountain to treat the mountains with considerable respect ... do all you can to protect them, keep them clean,” Hillary said in an interview.

“... people have tried to clean up the mountain and some good work has been done. But it is not enough. There is still a lot to be done to keep mountains like Everest clean.”

The list of climbers who have conquered Everest include a 70-year-old man, a blind person, a man with an artificial leg and the youngest -- a 16-year-old boy. Many have made multiple ascents and one sherpa has climbed it 16 times. “I would have to say if you attempt Mount Everest with considerable care and don't get carried away ... the satisfaction from climbing the mountain is very considerable,” Hillary added, sitting under a portrait of himself with an ice, axe and ropes.

Once is enough for Bada Saheb: But for Hillary, now 87, once was enough.

“Well, Tenzing and I talked about this. And Tenzing said ‘We have climbed it once and it is the first time it has been climbed. Why do it again?’.

“To me, there is little virtue really in climbing Mount Everest many, many times,” he said.

Tenzing died in 1986 aged 72.

Although Hillary never climbed Everest again, he did not turn his back on Nepal.

The former beekeeper lives in New Zealand, but makes regular trips to Nepal where he runs a charity that has set up 27 schools.

His Himalayan Trust also supports dozens of other schools and two hospitals in the remote Solukhumbhu region, home to Mount Everest and to the sherpas, the yak-herding tribe known for their climbing skills.

“I know I have been very fortunate in having many opportunities for adventurous activities,” Hillary said. “But more than anything I am very, very pleased at the work I have done with the sherpas.” Ang Rita Sherpa, who works for the trust, was one of the first to graduate from a school Hillary opened in 1960.

“Had it not been for the Bada Saheb I would only be a yak herder,” said Sherpa, referring to Hillary by a local term used as a mark of respect to the Everest hero. “He is like a godfather to us.”—Reuters