On the City Wall in Xi'an. This wall is one of the best preserved city walls in China. It was founded during the Tangdynastin (618-907). It is 12 meters high and 12 meters wide, surrounding the old town. It has four majestic gates, Anyuan (harmony) in the north, Changle (eternal happiness) in the east, Yongning (eternal peace) in the south and Anding (harmony and peace) in the west.