1. Qinghai-Tibet Railway from Xining to Lhasa, Tibet Autonomous Region
Few trains can take your breath away, but climbing to more than 5,200 metres, the Qinghai-Tibet railway from Xining to Lhasa can leave passengers more than a little tight in the chest. On the highest train in the world, compartments are fitted with gold nozzles pumping in purified oxygen to alleviate the symptoms of altitude sickness as passengers gaze at the yellow plateau and electric-blue skies. Suede-soft mountains are dusted with snow and raggedy-looking yaks dot the landscape, coloured prayer flags twisting in the breeze. As the train curls around the Kunlun Mountains, its interiors darken from the shadows of looming ice and snow before the final descent into Lhasa.