Gansu is a compound name first used in Song Dynasty China, of two Sui and Tang Dynasty prefectures: Gan (around Zhangye) and Su (around Jiuquan). The ruins of a Han Dynasty (202 BC - 220 AD) Chinese watchtower made of rammed earth at Dunhuang, Gansu province, the eastern edge of the Silk Road In prehistoric times, Gansu was host to a number of Neolithic cultures. The Dadiwan culture, from where numerous archaeologically significant artifacts have been excavated, flourished in the eastern end of Gansu from about 6000 BC to about 3000 BC. The Majiayao culture and part of the Qijia culture also took root in Gansu from 3100 BC to 2700 BC and 2400 BC to 1900 BC respectively. The Yuezhi originally lived in this area until they were forced to emigrate by the Xiongnu around 177 BCE. The Qin state, later to become the founding state of the Chinese empire, grew out from the southeastern part of Gansu, specifically the Tianshui area.     Hi Res Pic (196K)