The Ming Walls. During the Ming dynasty (1368 A.D.-1644 A.D.), Xi'an was refurbished and returned to prominence as a center of politics and trade. The Ming emperors rebuilt the walls, incorporating one corner left over from the Yuan dynasty in their design. While the architecture of the Ming is steadfastly angular, the curved rampart of Hun design adds grace to the overall effect. The walls are flat and straight, tempting one to a 15K jog.