Question: why is the forbidden city in china called the forbidden city

title: Forbidden City
text: The name `` Zijin Cheng '' is a name with significance on many levels . Zi , or `` Purple '' , refers to the North Star , which in ancient China was called the Ziwei Star , and in traditional Chinese astrology was the heavenly abode of the Celestial Emperor . The surrounding celestial region , the Ziwei Enclosure ( Chinese : 紫 微 垣 ; pinyin : Zǐwēiyuán ) , was the realm of the Celestial Emperor and his family . The Forbidden City , as the residence of the terrestrial emperor , was its earthly counterpart . Jin , or `` Forbidden '' , referred to the fact that no one could enter or leave the palace without the emperor 's permission . Cheng means a city . 

Answer: answer: The Forbidden City - `` Zijin Cheng '' meaning Jin , `` Forbidden '' and Cheng meaning city, referred to the fact that no one could enter or leave the palace without the emperor 's permission .
answer: Zi in Zijin Cheng, which means the Forbidden City, refers to  the Ziwei Star which was the heavenly abode of the Celestial Emperor and the the Forbidden City, as the residence of the terrestrial emperor, was its earthly counterpart. While Cheng means a city, the word Jin or forbidden refers to  the fact that no one could enter or leave the palace without the emperor's permission.