Half a century ago, Chinese farmers stumbled upon an enormous underground mausoleum full of life-size clay people, animals and military equipment. Archaeologists think that the tomb may be an entire replica of the Chinese city of Xi’an built to honor the first emperor of China, Qin Shi Huang, who died in 210 B.C.

Excavations within the tomb over the past five decades have continued to reveal more chambers full of statues, weapons, and skeletons of both humans and animals. But the actual grave of Emperor Qin, who conquered six warring states and unified China, has remained untouched for over two millennia.