北京城,据文献记载及考古资料证明,至今已有三千多年的历史了。明,清时的北京城是在元代“大都城”的基础上改造发展起来的。旧北京城分为内城和外城两部分,内城近方形,位北,外城仅包围内城的南端,两侧稍宽于内城,位南,所以北京城的平面呈“凸”字形。 Beijing City, according to historical records and archaeological data, has been more than 3,000 years of history. Ming and Qing Dynasty Beijing City was transformed and developed on the basis of the “Great Capital City” of the Yuan Dynasty. The old Beijing city is divided into inner city and outer city. The inner city is near to the square, and the north is located. The outer city only surrounds the southern end of the inner city. The two sides are slightly wider than the inner city and are located in the south, so the plane of the Beijing city is convex. "Glyph.