In the first of three dispatches from China, Sara Wheeler treks from Yunnan to Sichuan.

The shadow of a black-necked crane crossed the fretted light beneath the arms of a Himalayan yew. That curious evanescence of air particular to the Tibetan plateau sparkled through a quiet Chinese dawn, and my horseman yelled out the old song of the mountains.

I was trekking from Yunnan into Sichuan, two provinces now officially Chinese but once integral parts of the kingdom of Tibet. On the western flanks, both abut the foothills of the Himalaya, and the tang of snow was never far off, even when the sun shone. This corner of China – not in itself small, but dwarfed by the magnitude of the nation – characterises a facet of the Middle Kingdom forgotten in the dizzying rush to modernise…