Human Skull
© Mohamed Abd El Ghany/Reuters
An enormous ancient Chinese pyramid has been discovered in an 4,300-year-old lost city, which regularly hosted human sacrifices and was once one of the largest settlements in the world.

The astonishing find was documented in the latest issue of the journal Antiquity, in which researchers revealed that the newly excavated step pyramid is at least 230-ft high and covers a staggering 24 acres at its base.

The article, written by a team of professors at universities in China and California, says the city, now named "Shimao," flourished for five centuries across a 988-acre region surrounding the pyramid, making it one of the largest cities in the world.

The pyramid is decorated with eye symbols and part-human, part-animal figures which, the researchers say, could have given the pyramid religious power in the eyes of the Shimao citizens of the day. Both the city and pyramid were surrounded by a series of sophisticated defensive stone walls, ramparts and gates, which the team says indicates highly restricted access to the complex. Decapitated human heads were also discovered, suggesting human sacrifice was a popular tradition at the time.

"In the outer gateway of the eastern gate on the outer rampart alone, six pits containing decapitated human heads have been found," the researchers wrote.

The pyramid contains 11 steps, each of which are lined with stone. One of the steps was adorned with "extensive palaces." The archaeologists say the palaces were built of "rammed earth, with wooden pillars and roofing tiles." A gigantic water reservoir and domestic remains related to daily life were also found by the team.

The pyramid wasn't just a residential space for ruling Shimao elites, the researchers said. They also found evidence of ancient art and craft work, suggesting that the pyramid was used for artisanal or industrial craft production.