Mausoleum of Emperor Qin Shihuang was built from 246 BC t0 208 BC, by order of Qin Shihuang, the emperor of the first unified country of centralized power and various nationalities in the Chinese history. It is the first and largest imperial mausoleum with the most numerous sacrificial objects in China. The mausoleum is square in shape, with a flat top and ladder-shaped profile. It is 76 metres high, 345 metres long from east to west and 350 metres long from north to south. The total area of the mausoleum and its accompanying building relics is. 120,750 square meters. The grand accompanying sacrificial Terra Cotta pits, with a total area of 25,380 square metres, were constructed from 221 BC t0 209 BC. The pottery warriors and horses in the pits were organized in groups according to the army formation in the Qin Dynasty, which provided vivid materials for researching into the military establishment, fighting modes and army supplies in the Qin Dynasty. The excavation of the Terra Cotta Warriors and Horses is considered "the eighth wonder of the world" and "one of the most spectacular archaeological discoveries of the twentieth century". The realistic style of the Terra Cotta Warriors and Horses, which serves as a transitional art style in China's history of sculpture, has aroused the worldwide interest.