The Roof of the World

  I took this train from Xining, Qinghai and went all the way to Lhasa several years ago. It turned out to be one of the most amazing trips I have ever taken. Within the 12 hour travelling time (from 6 pm to 6 am the other morning) we travelled through one of the highest altitude plateau in the world (average elevation exceeding 4,500 metres according to Wikipedia) with fascinating sceneries outside the window.
  Please, trust me, try & visit this place in your lifetime :) you won't regret it.

Qinghai-Tibet Plateau