Tibetan Plateau is the world’s highest plateau, with an average altitude of 4,500 meters/ 14,750 ft. It’s known as the “roof of the world” and “Third Pole” due to high elevation. It is highly suggested to spend about 3 nights in Lhasa or Tsetang, the relatively lower altitude places of Tibet first before moving further to other higher altitude places.
Actually the lowest place in Tibet is Nyingchi with an elevation of 3,000 meters/ 9,843 ft, and the highest place in Tibet is Ngari, with an elevation of 4,500 meters/ 14,764 ft.
Click here to know elevation tibet