Mausoleum of Qin Shi Huang

34.3812°N, 109.2540°E.

The Mausoleum of Qin Shi Huang in Lintong District, Xi'an, Shaanxi Province, China — the earth-mound tomb of the first emperor of unified China, who reigned from 246 to 210 BCE. The visible mound covers a base of approximately 350 by 350 metres and rises 76 metres — making it one of the largest single funerary structures in the world by volume — and is constructed of rammed earth in successive horizontal lifts. The tomb chamber itself has never been excavated; ground-penetrating radar and mercury-vapour soil sampling conducted by Chinese state archaeologists between 2002 and 2008 confirmed the existence of a large central chamber and elevated mercury concentrations consistent with the description in Sima Qian's Records of the Grand Historian (~94 BCE) of an interior featuring rivers and seas of liquid mercury and a vaulted ceiling set with pearls representing the constellations. The famous Terracotta Army was discovered in 1974 by farmers digging a well 1.5 kilometres east of the mound — over 8,000 figures excavated to date, none of them inside the central tomb.

A pyramid the size of a small mountain whose interior nobody has opened in twenty-two centuries.