What's so special about Pingyao ancient city?

This ancient city is very different from ordinary cities. It is said that the former four streets, East, West, North and South, did not directly face the city gate because of the need of military defense. Later, according to Feng Shui, there was another saying-the head and tail of commercial street should not be relative to each other, so as not to wash away wealth, so the streets running through the north and south are not in a straight line, and the south street leans slightly to the east and the north street deviates to the west. More interestingly, the north city in Guiwei is the lowest place in the city, and all the wastewater in the city flows out from here.