Everest Lhotse and Nuptse. Left: Cloud walking Centre: Everest, Lhotse and Nuptse from Kala Pattar at 6pm, the last light of the day over the world's highest mountain ridge. Right: The Lhotse Nuptse Wall the highest unclimbed mountain face in the world. Above 8000 metres there is insufficient oxygen to sustain life. At these heights mountain winds reach over 150kms. Mixing air layers creates turbulence in the jet stream. © John Beatty