Introduction to the rockery: Since the Ouyuan Garden is the east garden of King Heng, its layout and scale are similar to the Imperial Garden in the palace. Especially the rockery in the garden is ingeniously conceived and skillfully crafted. Its artistic conception and stacking stone style techniques are completely consistent with those of Zhongnanhai Yingtai. Garden experts infer that Qingzhou Ouyuan Garden is the work of Zhang Ran, a descendant of Zhang Nanyuan, a famous Chinese gardener in the Ming Dynasty.