The Cloud-and-Dragon Staircase Stone stands as a quintessential example of ancient craftsmanship, located proudly behind the Hall of Preserving Harmony (Baohe Dian) in Beijing's iconic Forbidden City.

Sourced from Dashuowo village in the Fangshan district on the outskirts of Beijing, the structure is carved from four blocks of Aiyeqing, a green stone dating back to the Ming Dynasty. The largest block measures approximately over 16 meters long, 3.07 meters wide, and 1.7 meters thick. It weighs over 200 tonnes and is the largest structural component in the Forbidden City. The wisdom behind this monumental work is best demonstrated in the techniques used for its transportation and carving.

To transport the stone, craftsmen combined natural winter conditions with fundamental physics principles to complete an about 70-km haul. According to the historical record Notes on the Construction of the Two Palaces (Lianggong Dingjian Ji), the process was executed in three stages.

First, they constructed "dry boats" or rectangular wooden frameworks designed to carry the stone. The bases of these frames were made of wooden beams that created broad surface areas to evenly distribute the immense weight of the stones and prevented their damage. Second, wells were dug along the route at intervals of about two km. In winter, water was hauled from these wells and splashed onto the road surface to create a sheet of ice, significantly reducing sliding friction. Third was the towing process. Teams of horses dragged the "dry boats" across the ice, advancing about eight to 10 km a day.

In terms of carving technique, the Cloud-and-Dragon Staircase Stone combines various craftsmanship styles that are in perfect harmony with each other. The soaring dragons are carved in high relief. By carving away the background material, the dragon motifs stand out in bold relief, creating a powerful three-dimensional effect that makes the nine dragons appear remarkably lifelike. Conversely, the auspicious clouds and waves of Treasure Mountain are rendered in low relief. Only the areas immediately surrounding the motifs are incised, creating a subtle effect that contrasts with the dynamic dragons. Moreover, the scrolling vine patterns on either side of the stone are rendered in flat relief, conveying a sense of fluid movement and vitality.

The monumental carving embodies the spirit of ancient craftsmanship — a spirit that balances adherence to established aesthetic norms with innovative, era-specific techniques. As such, it serves as an invaluable reference for preserving and sharing intangible cultural heritage skills.