A veteran Mexican climber was confirmed today as the first person to climb Mount Everest from both sides of the mountain in the same season.
33-year-old David Liano Gonzalez reached the top of Mount Everest on May 11 from the south side, and days later started his second successful ascent of the world's highest mountain from the north side.
Gonzalez, who says he has now climbed Mount Everest five times in total, was awarded the official record certificate from Guinness World Records at a ceremony in the Nepal capital on Thursday.
"I am very happy to have set this record," Gonzalez told reporters.
Confirmation of the feat comes after Nepal on Wednesday marked 60 years since the first ascent of Mount Everest, with celebrations honouring the now legendary climbers Edmund Hillary and Tenzing Norgay.
Around 3,500 people have reached the top of Mount Everest since the first conquest in 1953, and climbing to the roof of the world has become a lucrative industry for impoverished Nepal.
"He (Gonzalez) summited Mount Everest on 11 May 2013 from Nepal (the south side) and on May 19 from Tibet (the north side), becoming the first person in one single expedition season to do so," said Ang Tshering Sherpa, founder of Asian Trekking, the company that organised the expedition.
Gonzalez said that after his first ascent from the Nepal side, he descended to the Mount Everest base camp and flew to Kathmandu, before making an overland trip to Tibet for his second successful bid.
There are at least four routes to the top of the 8,848-metre (29,029 ft) mountain. But most commercially guided expeditions follow the Southeast Ridge in the Nepal side and the Northeast Ridge in the Tibetan side of China.
The summit season on Mount Everest begins every year in late April, when a small window between spring and the summer monsoon offers the best conditions for making the ascent.
Around 540 have reached the top this year, including an octogenarian, the first female amputee, the first women from Saudi Arabia and Pakistan, and the first armless man.