中国古代的城市大都具有两个特征:一个特征是,它是一个地区的政治,经济中心,是人们的集中居住地,另一个特征就是,它往往是军事上争夺的焦点,许多战争就围绕着一个城市的得失而进行,它们具备着一定的军事功能。因而古代的城市大多为坚实的城墙所围绕,城墙成为城市的标志。 Most ancient Chinese cities have two characteristics: one is that it is the political and economic center of a region and the central place where people live. Another characteristic is that it is often the focus of military scramble. Many wars surround the A city gains and losses, they have a certain military function. Thus the ancient city mostly surrounded by a solid wall, the city walls become a sign.