The Silk Road spanned the Asian continent and represented a form of global economy when the known world was smaller but more difficult to traverse than nowadays. A network of mostly land but also sea trading routes, the Silk Road stretched from China to Korea and Japan in the east, and connected China through Central Asia to India in the south and to Turkey and Italy in the west. The Silk Road system has existed for over 2,000 years, with specific routes changing over time. For millennia, highly valued silk, cotton, wool, glass, jade, lapis lazuli, gold, silver, salt, spices, tea, herbal medicines, foods, fruits, flowers, horses, musical instruments, and architectural, philosophical, and religious ideas traveled those routes. The roads themselves were generally in poor condition. Travelers in caravans had to brave bleak deserts, high mountains, extreme heat and cold. They had to face bandits and raiders, imprisonment, starvation, and other forms of deprivation.