THE SILK ROAD was actually a perilous network of routes. It was hazardous to monks and pilgrims carrying Buddhist teachings between India and China and even more hazardous to traders, who intended to exchange gold, wool, horses, jade, and glass for silk. The road started in what is now Xi'an, in Shaanxi Province, traversed a barren crust of earth through treacherous mountains and desert across Central Asia to Antioch and Tyre; the last lap, to Europe and Egypt, was by water to other Mediterranean ports.