Archaeologists have discovered altar relics outside the walls of the Shimao Ruins - a Neolithic city in Shenmu County, in the north of Shaanxi province, northwest China.
     Shimao Ruins were discovered in 1976, but archaeologists did not conduct a thorough survey until last year, when they excavated over 80 human skulls.
     An initial survey showed the eight-meter-high altar had a three-tiered structure with a stone base 90 meters long. Jade relics and pits for offerings as deep as three meters were found nearby. Archaeologists have collected some jade for further research.
     The city was found to have inner and outer structures, and the walls surrounding the outer city extend over four square kilometers. The city was built about 4,300 years ago and abandoned roughly 300 years later.

Shanghai Daily (20 February 2014), China Daily (22 February 2014)