Qin Shi Huang was thirteen when construction began. Sima Qian, in his most famous work, Shiji, completed a century after the mausoleum completion, wrote that the First Emperor was buried with palaces, scenic towers, officials, valuable utensils and 'wonderful objects,' with 100 rivers fashioned in mercury and above this heavenly bodies below which he wrote were 'the features of the earth.' Recent scientific work at the site has shown high levels of mercury in the soil on and around Mount Lishan, appearing to add credence to the writing of ancient historian Sima Qian. The tomb of Shi Huang Di is near an earthen pyramid 76 meters tall and nearly 350 square meters. The tomb remains unopened, in the hope that it will remain intact. Only a portion of the site is presently excavated.