Mount Everest is one of the most recognisable mountains in the world. Every year hundreds of people attempt to reach its summit - many lose their lives.
People from around the world are captivated by its height - some 8848 metres above sea level - and the adventurous, driven, mountain climbers who take it on embody the physical and mental extremes that test human capabilities.
Last week, 16 Sherpa were killed in an avalanche during the deadliest day on the mountain's slopes in recorded history.
Today we look at 12 extreme facts that you might not know about Mount Everest.
1. Its status as tallest mountain was not discovered until the 1800s
Launched in 1802 by the British, the Great Trigonometrical Survey mapped the Indian subcontinent. Rugged terrain, illness and extreme weather conditions slowed the work, but it was soon discovered that the Himalayas were the world's highest mountain range - previously the Andes were thought to be the highest. Its height was calculated in 1856, and in 1999 another survey using GPS technology discovered that the team was only off by 6 metres.
2. It was named after a British Surveyor
In 1847 Andrew Waugh, British Surveyor General of India named Mount Everest Peak B, while his assistant gave the peaks various roman numerals to name them. In 1865, Waugh proposed that the Royal Geographical Society should name the mountain after his predecessor George Everest because it was too difficult to pronounce its Hindi name. His request was granted.
Climbers make their way to the summit of Mount Everest. Photo / AP/Alpenglow Expeditions
3. Mount Everest has more than one name
The Nepalese call the mountain Sagarmatha, or "goddess of the sky", whereas the Tibetans call it Chomolungma or "mother goddess of the universe".
4. Mount Everest is littered with corpses
The "death zone" of the perilous mountain begins at 8000 metres high and it is estimated that some 200 bodies remain in twisted positions from avalanches, falls, acute mountain sickness, exposure or frostbite.
The mother of a Nepalese mountaineer Ang Kaji Sherpa who was killed in an avalanche on Mount Everest. Photo / AP
5. The temperature on the mountain never goes above freezing point
Mount Everest averages -19C in summer and -36C in winter.
6. A dead body called Green Boots indicates how close you are to the summit
In 1996 an Indian climber (whose identity is still disputed) became separated from his group and sought respite in a cave where he literally froze to death. The high winds on the mountain have since blown his body so that he now lies face down in the snow.
7. You can tweet from the summit
The first tweet from the top of Mount Everest was sent by Kenton Cool in 2011. "Everest summit no 9! 1st tweet from the top of the world thanks to a weak 3G signal", he tweeted.
Everest summit no 9! 1st tweet from the top of the world thanks to a weak 3G signal & the awesome Samsung Galaxy S2 handset! @samsunguk— Kenton Cool (@KentonCool) May 6, 2011
8. Google couldn't map the summit without help
Although now mapped by Google, it took a team 12 days to capture images for Google maps.
9. It costs over $30,000 to climb Mount Everest
Although it is getting cheaper, mountain climbing is for those with money to spare - travel costs, equipment, payments to Nepalese Ministry of Tourism and Civil Aviation, oxygen, base camp support and hiring a Sherpa mean that it is an expensive undertaking. It can be made cheaper by climbing during the off-season or travelling without support.
10. Mount Everest "firsts" are fiercely sought after
Ever since Sir Edmund Hillary and his Sherpa guide Tenzing Norgay became the first adventurers to reach the summit of the mountain, the old, the young, the daring, and the romantics have all endeavoured to make their climb all the more special by being the first. Whether it is Junko Tabei (the first woman), Tom Whittaker (the first amputee), or Stephan Gatt (the first person to snowboard down its slopes), there's no end to the drive to capture an Everest first.
One of the more unusual was the wedding of Nepalese couple Moni Mule Pati and Pem Dorjeee Sherpa in 2004.
Sir Edmund Hillary. Photo / Wayne Drought
11. The appeal of Mount Everest may well be genetic
The sons of both Hillary and Norgay have both followed in their father's footsteps and climbed its treacherous heights. Sir Edmund Hillary's son Peter climbed the mountain in 1990, making them the first father and son duo to do so. In 1996, Jamling Tenzing Norgay followed in his father's footsteps and made it to summit.
12. Dead bodies are not the only litter problem on the mountain
Oxygen bottles, camping equipment, rope, beer cans and even remnants from a crashed helicopter have caused problems for this naturally beautiful landscape. In an effort to clean up the rubbish, 65 people and 75 yaks carried down eight tons of trash from its slopes. An art exhibition was made from the trash in an effort to highlight the issue.