SHIMAO, CHINA — Archeologists have discovered the remains of a 4,000-year-old lost city on a ridge above China's Tuwei River.

Researchers found a massive step pyramid that is at least 230 feet high and stretches 59 acres at its base and published the results in the journal Antiquity, according to Live Science.

According to archeologists, a city flourished around the pyramid for five centuries, and at one point encompassed an area of 988 acres. Researchers have named the city "Shimao."
The pyramid was built out of a loess hill, and had 11 steps tapering as they ascend. It was guarded by an inner and outer wall.

According to the researchers, atop the pyramid "were extensive palaces built of rammed earth, with wooden pillars and roofing tiles, a gigantic water reservoir, and domestic remains related to daily life."
The researchers believe the ruling class lived on top of the pyramid, where artisanal or industrial crafts were produced.

The remains of several human sacrifices were also discovered at Shimao.