More than 300 items used by prehistoric people in their daily life 4,000 years ago. [Photo/Xinhua]

The Beiyuan relic site, covering 25,000 square meters, was first excavated in 2013. This year about 40 people, led by the Ningxia regional archaeological institute, conducted a second excavation to learn more about Neolithic culture and development in the region.

Experts searched 11 houses - one cave dwelling and ten kivas - 151 pits, three kilns and a tomb. The kivas were square in shape, with a round cooking range at the center and painted white with lime.