Squeezing for 650 miles (1,000km) between the Tibetan Plateau and dunes of the Gobi Desert, the Hexi Corridor was the crux of the Silk Route’s northern branch. A necklace of oases dotted along this ancient trackway enabled caravans to travel from Lanzhou to the so-called ‘Jade Gate’ in the far west, where the fort of Jiayuguan protected the corridor’s narrowest point – the limit of Chinese civilization.

Framed by an astonishing backdrop of snow-capped mountains, the fortress survives and has been immaculately restored in recent years, standing as an evocative reminder of the Silk Route’s heyday. It was through the fort’s infamous northwestern gateway that Chinese people banished from the empire would leave their homeland to face the sandy wastes of the Gobi Desert.