A monk returns home by taking the train from Lhasa, capital of Southwest China's Tibet autonomous region, to Xining, capital of Northwest China's Qinghai province, on the Qinghai-Tibet railway on May 27, 2016. Since the opening of the railway a decade ago, the number of passengers paying pilgrimage to Lhasa has been on the rise. From early December to the end of January the next year, more than 60 per cent of passengers on the train K9801, heading from Xining to Lhasa, were pilgrims. [Photo/Xinhua]

About 1,375 years ago, Wen Cheng, a Han princess in the Tang Dynasty (AD 618-907), took nearly three years to travel the 2,800 kilometers from today's Xi'an, Shaanxi province, to Lhasa, Tibet, to marry Songtsan Gampo, the Tibetan king.

Now, thanks to the opening of the Qinghai-Tibet Railway 10 years ago, the trip takes just 32 hours.

The railway is 1,956 kilometers long. At its highest point, it is 5,072 meters above sea level. It is the world's highest line, and the longest built on a single plateau. It is the first railway connecting Tibet with the rest of world.