Located at the northern foot of Lishan Mountain, 35 kilometers northeast of Xi'an, Shaanxi Province, Qinshihuang Mausoleum is the tomb of Emperor Qinshihuang, founder of the first unified empire in Chinese history during the 3rd century BCE. Begun in 246 BCE the grave mound survives to a height of 51.3 meters within a rectangular, double-walled enclosure oriented north-south. Nearly 200 accompanying pits containing thousands of life-size terra cotta soldiers, terra cotta horses and bronze chariots and weapons - a world-renowned discovery - together with burial tombs and architectural remains total over 600 sites within the property area of 56.25 square kilometers. According to the historian Sima Qian (c. 145 - 95 BCE), workers from every province of the Empire toiled unceasingly until the death of the Emperor in 210 in order to construct a subterranean city within a gigantic mound.