Messner's 1980 oxygenless solo Everest ascent
In August 1980, during the monsoon, Messner climbed Everest alone from Tibet. He had no supplemental oxygen, no rope partner, no fixed camps and no support above advanced base camp, where his companion Nena Holguín waited. After surviving a fall into a crevasse on the first night, he crossed the north face into the Great Couloir because deep snow blocked the ridge, reached the summit on 20 August, and descended exhausted and hallucinating.