The Forbidden City

The forbidden City, the imperial palace complex of the last two dynasties of China, lies at the center of present-day Beijing. it was from here that fourteen Ming and ten Qing dynasty emperors issued edicts and ruled China for 491 years.
The theory of yin and yang have a long continuous history in Chinese civilization. It says yin and yang is the way of heaven and earth, meaning that everything can be divided into the two mutually opposite and independent elements of yin and yang. For example, the pair of above and below, front and back, odd and even, positive and negative, are all the embodiments of this theory.
The architectural design of Forbidden City directly reflects the principles of yin and yang. Of the two sector of the Forbidden City, the Outer Court signifies yang while the Inner Court embodies yin. This belong so, odd numbers dominate the design of Outer Court and even numbers prevail in the Inner Court.

further interests about fractal geometry

In the self-similar world, the smaller part is the reduced-size copy of the whole. It is known that fractal geometry and fractal architecture has many applications in the western art and architecture, from the pattern to structure, from facade to plans. But actually, in the east countries, you can find the very close relationship between fractal theory and Chinese imperial urban and building designs. Although these designs have already existed for a long time, the essence of the designing method surprisingly approach the fractal geometry. I think it is very interesting to make a bridge from western architecture theory to Chinese classical architecture styles. 
In addition, this pattern, obviously, could allow the space more interesting and have more possibility. In other words, the larger space could be considered as the container of the smaller one. From a broader perspective, this relationship could create a mysterious organized pattern. And behind this pattern, there may be some other metaphor and symbol that relate the cultural background of the city and palace. For example, the most famous pattern for urban design in ancient china was nine grids, which possessed the features of symmetry and self-similarity. As far as I know, it came from a Chinese scientist’s research about the universe and space in ancient china. With the functional and aesthetic value, this form gradually became the main architecture pattern in the design of imperial city and palace.