Dou Gong or “cap and block” is known to be a remarkable structural element of joining wooden brackets. It is one of the greatest elements in Chinese traditional architecture. The pieces are fixed together by only the joints made in the wood. It did not use nails or glue, it was held together because of the accuracy and excellence of the woodworking. In the Forbidden City, all of the buildings used this technique. William Watson, the author of The Art of China, states that, “the purpose of dou gong is to provide added support for the weight of the horizontal beams that span the vertical columns or pillars by transferring the weight on horizontal beams over a larger area to the vertical columns. This process can be repeated many times, and rise many stories. Adding multiple sets of interlocking brackets reduces the amount of strain on the horizontal beams when transferring their weight to a column”. Numerous dou gong lets structures to be flexible and to resist damage from earthquakes.