"'Hutong' is a kind of ancient city alley or lane typical in Beijing, where the number of hutongs may run into several thousand. They are around the Forbidden City, many of which were built during the three dynasties of Yuan, Ming and Qing. At the prime of these dynasties, the emperors, in order to establish supreme power for themselves, planned the city and arranged the residential areas according to the etiquette systems of the Zhou Dynasty. The center of the city of Beijing was the royal palace -- the Forbidden City. All the main streets were arranged longitudinally and latitudinally. There have been two kinds of hutong. One kind, usually referred to as the regular hutong, was centered closely to the east and west of the palace and orderly arranged alongside the streets. Most of the residents who lived in these hutongs were people of imperial kinsmen and aristocrats. Another kind, the simple and crude hutong was mostly far located to the north and south of the palace. The residents there were merchants and other ordinary people. The main buildings in the hutong were almost all 'quadrangles' -- a kind of enclosure of building complex formed by four houses standing on the four sides. The quadrangles varied in size and design with the social standing of the residents. The big quadrangles of the high ranking officials and wealthy merchants were specially built with roof beams and pillars all beautifully carved and painted, each with a front yard and a back yard. However, the ordinary people's quadrangles were simply built with small gates and low houses. Hutongs, in fact, are passageways formed by many closely arranged quadrangles of different sizes. The specially built quadrangles all face to the south for better lighting. As a result, a lot of hutongs run from east to west. Between the big hutongs there have been many small ones going north and south, for convenient passage. There fore, the city of Beijing is like a magnified quadrangle, symmetrically and neatly arranged, and surrounded rectangularly by high walls."