Chinese archaeologists have found two prehistoric settlements, dating back to more than 4,000 years ago, at the Puchengdian ruins in central China's Henan province. The Puchengdian site were designated as the first group provincial-level cultural relic protection units of Henan in 1963. With an area of 150,000 square meters, the site contain relics of the Neolithic age and the Xia, Shang, Zhou and Han dynasties. One of them was confirmed by archaeologists to belong to the late period of the Longshan culture (3000 BCE-1700 BCE), the other belongs to the early period of the Erlitou culture (1900 BCE-1500 BCE).