Ancient city wall in Xi'an, Shaanxi province. Xi'an, a city with over 3,100 years of history, served as the capital for 13 dynasties in Chinese history. It boasts well-preserved ancient city walls. [By Yuan Fang/China.org.cn]

Ancient city wall in Xi'an, Shaanxi province. Xi'an, a city with over 3,100 years of history, served as the capital for 13 dynasties in Chinese history. It boasts well-preserved ancient city walls. [By Yuan Fang/China.org.cn]

Ancient city wall in Xi'an, Shaanxi province. Xi'an, a city with over 3,100 years of history, served as the capital for 13 dynasties in Chinese history. It boasts well-preserved ancient city walls. [By Yuan Fang/China.org.cn]

Ancient city wall in Xi'an, Shaanxi province. Xi'an, a city with over 3,100 years of history, served as the capital for 13 dynasties in Chinese history. It boasts well-preserved ancient city walls. [By Yuan Fang/China.org.cn]

Ancient city wall in Xi'an, Shaanxi province. Xi'an, a city with over 3,100 years of history, served as the capital for 13 dynasties in Chinese history. It boasts well-preserved ancient city walls. [By Yuan Fang/China.org.cn]