Lhagba La  Lhagba La or Lhakpa La (meaning "Windy Gap") is a col about northeast of Mount Everest in the Tibet Autonomous Region. It was unknown to local inhabitants until it was discovered and named by the 1921 British Mount Everest reconnaissance expedition when reconnoitring a route to climb the mountain. Lhagba La is the starting point of the Kada Glacier which descends eastwards along the valley towards Kada. The Kada River is a tributary of the Arun River. On the western side of the col is the East Rongbuk Glacier which flows north from Everest. Lhagba Pool, below and to southwest, is reportedly the second highest lake in the world. Expeditions attempting Everest via the North Col generally arrive up the East Rongbuk Glacier and so do not reach Lhagba La at all. However, when George Mallory and Guy Bullock were trying to reach the North Col, the route from Rongbuk was unknown to them. Instead they approached from the east only to find the glacier did not extend to the North Col. The climbing team eventually had to cross the pass and descend some to the East Rongbuk Glacier before ascending to the North Col. Their discovery allowed the 1922 British Mount Everest expedition to take the more direct route from the north. The well known Yeti footprints were found in this region for the first time in the world probably at the beginning of 19th century. Later it came up into the light through the media. This mystery of "Yeti" is still unsolved.