Immediately after the Annapurna Trek we planned to travel to Lhasa, the capital of Tibet, by using 4x4 Jeeps. The departure was in Kathmandu, Nepal, and finally the preceding trek was very useful for not getting High Mountain Sickness. The encountered altitude was always around 4000m.
The Tibetans are one of the most inviting people and the salty yak- butter-tea, compared to what is written in most books (tastes like old socks), was even delicious. Give it a try!
During our visit the new Chinese railway Beijing-Lhasa was about to be accomplished. This will unfortunately open the doors to a large Chinese immigration into this rich tradition-bound country. So get there as fast as you can.