In December 1929, a Chinese paleoanthropologist named Pei Wenzhong discovered a complete skull of "Peking Man" on Dragon Bone Hill, northwest of Zhoukoudian, in the southwest suburbs of Beijing. Later, archaeologists unearthed 40-odd individually fossilized skeletons of "Peking Man", male, female, old and young, at the same site. Zhoukoudian became a common site for human remains with the most abundant fossils in the world from the same period.
The discovery pushed the history of Beijing's civilization back to some 600,000 years. These fossilized remains prove that "Peking Man" was a primitive man in an evolutionary process from ancient ape to modern man, and is the ancestor of the Chinese nation.
Inside the 140-meter-long Peking Man Cave, stratum accumulation was a depth of 40 meters. The inhabitants spanning more than 300,000 years left their remains, stone tools and traces of fire here. The bones of Peking Man discovered in the cave in the hill's north face include six complete or relatively complete skulls, eight skull fragments, six pieces of facial bone, 15 mandibles, 153 teeth, seven sections of broken femur, one broken shinbone, three pieces of upper arm bone, one clavicle and one wrist bone belonging to more than 40 individuals of different ages and sexes. Additionally, 118 animal fossils have been found in the cave on the north face of the hill.
On Dragon Bone Hill were also found fossilized remains of the Upper Cave Man, who lived 18,000 years ago, as well as sites of New Cave Man, who lived between Peking Man and Upper Cave Man.
The period when Peking Man lived was an important period in the evolutionary history of modern humanity, especially in East Asia. The period was an important and controversial area for research in international academic circles, so human fossils of this period were very valuable.
In 1987, the Zhoukoudian caves were listed as one of the world cultural heritage sites.