BETWEEN MESOPOTAMIA and China stretched Central Asia, large, barren, hostile—a wasteland. Through this vast area, the 1 link that allowed the 2 civilizations to trade with each other was the loosely defined cluster of trails known as the Silk Road. Even today, the Silk Road runs through 1 of the harshest desert environments in the world, with little water or vegetation or life. It is sandy, and sandstorms bury everything in their way. The local inhabitants refer to the Taklimakan Desert as “the Land of Irrevocable Death.” Locals stayed near the Silk Road and the other paths around the edge of the desert. Northeast of the Taklimakan is the Gobi Desert, less desolate and dry, but still formidable. To the south are the Himalayas, Karakourum, and Kunkun, the highest mountain ranges in the world. Another barrier between west and east is the Pamir Knot, several mountain ranges. including the Tian Shan and Pamir. The easiest access from the east is by the comparatively fertile Gansu Corridor, which lies between the Tibetan High Plateau and the Gobi Desert and Mongolian plateau. Travelers from the south had to cross ice-laden passes in the Himalayas and the Pamir Knot. China and Mesopotamia developed civilization and commerce, Mesopotamia first, with China developing later because the terrain was more difficult. The Qin Dynasty established a central government for the individual states. The capital was at Changan (presentday Xian). The Han Dynasty first explored to the west, when Zhang Qian sought to ally with the Yuezhi tribe in the west. The 13-year journey began in 138 Before Common Era He returned with no ally but with information about horses and tribes hitherto unknown. The emperor sent more expeditions in search of horses and luxuries. Although Zhang Qian is titled as the father of the Silk Road, he was not the first explorer. Even before, Chinese merchants were providing small amounts of Chinese goods to the west via the Silk Road.