Urban PlanningChang’an in Tang times attracted merchants, pilgrims, and students from all over East Asia. The city was laid out on a square grid (left) and divided into walled wards, the gates to which were closed at night. Temples were found throughout the city, but trade was limited to two government-supervised markets. In the eighth and ninth centuries the Japanese copied the general plan of Chang’an in designing their capitals — first at Nara, then at Heian, shown on the right. (Cradles of Civilization/Visual Connection Archive)