Zhoukoudian is widely regarded as having the oldest reliable evidence
for the controlled use of fire by humans. A reexamination of the evide
nce in Layer 10, the earliest archaeological horizon in the site, show
s that burned and unburned bones are present in the same Layer with st
one tools. However, no ash or charcoal remnants could be detected. Hen
ce, although indirect evidence for burning is present, there is no dir
ect evidence for in situ burning.