Introduction to the caisson: The Twenty-Eight Constellations can be found in many Taoist buildings in China, but they basically exist in the form of sculptures. Like the Nuodeng Yuhuang Pavilion, they exist in the form of paintings on the attic caisson (ceiling). Yes, Nuodeng Yuhuang Pavilion is unique. The four wooden pillars from the first floor to the top of the third floor, with a height of more than 20 meters, are all carved from one thousand-year-old wood. In the past, there were four five-clawed golden dragons carved on the wooden pillars, circling from the first floor to the third floor. Unfortunately, they were destroyed during the Cultural Revolution. Now you can vaguely see the dragon patterns on the pillars.