The document discusses the Silk Road, an ancient network of trade routes connecting China to the Mediterranean region. It details how the Silk Road facilitated cultural exchange and the spread of religions from its inception in the 2nd century BC until its decline in the late Middle Ages. Specifically, it highlights that the Silk Road's peak was during the Tang Dynasty in China when the capital Changan became a cosmopolitan center of trade. It then describes how the fragmentation of the Mongol Empire and outbreaks of plague contributed to the Silk Road's fading importance by the 15th century. The document concludes by noting growing modern interest in restoring and promoting tourism along the historic Silk Road trade routes.