A traditional architectural feature from the Han dynasty, Zaojing is often found in palaces and temples. It consists of a sunken, square, polygonal, or circular coffer in the center of the ceiling. The carvings inside are incredibly intricate, luxurious, and exquisitely detailed. This unique structure, known as "Zaojing" (coffered ceiling), can be seen in the Hall of Supreme Harmony and the Hall of Mental Cultivation within the Forbidden City. The construction technique for Zaojing is highly complex—artisans did not use nails but instead relied on mortise-and-tenon joints and interlocking brackets to assemble the structure. When looking up from below, the ceiling resembles an inverted well.

 

The Chinese have long believed in the concept of a "round sky and square earth," which influenced their architectural principles. Ancient Chinese builders designed ceilings not only for aesthetic purposes but also as a symbolic representation of heaven, hoping to bring peace, safety, and protection from disasters such as fire. Zaojing first appeared over 2,000 years ago and was initially used to decorate the ceilings of Han dynasty tomb chambers. Later, it became a prominent feature in royal and religious architecture.

 

During the Ming dynasty, the structure and artistic style of Zaojing advanced significantly, becoming highly refined and magnificent. By the Qing dynasty, most Zaojing featured elaborate carvings of coiled dragons, rendered with remarkable realism. Due to this artistic evolution, Zaojing came to be known as "Longjing" (Dragon Well)