Turpan is an extensive oasis located in Xinjiang Province. northwestern China. It is the ancestral country of the Uyghur Turks who still live there today. This oasis is one of the several stages of the ancient Silk Road that crossed the very arduous Taklimakan desert, in the endoeric Tarim basin, whose lowest point is 154 m below sea level. This oasis was intentionally created by digging underground canals, called karez, to collect groundwater, preventing its evaporation. In 1983 there where known 1,154 tunnels, each averaging 3 km long, for a total of 3,000 km, most of which are still active. Within this area there are also the remains of numerous ancient rock-cut settlements, including the suggestive “stone city” of Jahoe.

Bixio R., Castellani V., Dragoni W., 1999, ‘A caccia di cunicoli: dalla Cappadocia allo Xinjiang’, in rivista Speleologia, n°40, Società Speleologica Italiana, Bologna, pp. 85-89