The second picture in this series shows the Spirit Road from within the Mysterious Gate at the entrance. This type of gate is open to the four directions with the central space devoted to a huge statue of the sacred turtle with a stone tablet rising out of its back. The inscriptions on this tablet memorializes the sacred Pattern/Templates (archetypes) in the form of the trigrams of the Yijing (Book of Changes) given to the first legendary emperor, Fuxi, by this turtle as it rose out of the Yellow River at the dawn of creation.
The Mysterious Gate is situated just before entry onto the Spirit Road itself with the Dragon Wind Gate opening to the North and the area of the imperial tombs. Both of these gates have openings representing the Five Phases of acupuncture. Because the Mysterious Gate opens to the four directions, it creates a vertical opening between Heaven and Earth and channels the spirit onto the earth according to the commands it receives from Heaven. As Son of Heaven, the emperor (spirit) issues these commands from the origin of spirit between the poles of Yin and Yang (the archetypes of the Five Phases).
The Dragon Gate has five openings lined up in a row so that this gate channels the Qi between the North and the South along the vertical pole of the earth. These two gates together represent the Yin and Yang aspects of the "Spirit Gate" in acupuncture. "Spirit Gate" is the name of one of the important acupuncture points relating to the Heart where the spirit is said to reside. One of the symbols of the emperor is the dragon. In turn, the emperor is the main symbol for the spirit residing in the Heart. The Dragon Gate, therefore, is the gate through which the emperor (spirit) passes to rest, while the Mysterious Gate is where the commands of the emperor (spirit) issue forth into life. The Mysterious Gate is, therefore, located on the southern end of the Spirit Road and is related to the functions of the acupuncture point, Lung 7. Through the Pattern/Templates of Yin-Yang and the Five Phases all things, in accordance with the spirit, come into being.
For a detailed explanation of how the symbols of the Spirit Gate and the Spirit Road relate to the practice of acupuncture on the Spirit level
The Twelve Spirit Points of Acupuncture
For a detailed explanation of how the symbols of the Mysterious Gate relates to the energetic functions of Lung 7
For a detailed explanation of how the Mysterious Gate is related to ancient Chinese philosophy
See the section in this slide show on Wudang/Purple Cloud Palace for a further explanation as well as a picture of this turtle in another location.