In 2003, archaeological excavation revealed on the site of Taosi walled-town the northern entrance of the core building complex in the palace area of the early and middle Taosi culture. The vestiges comprise zigzag road-foundations of shutter-rammed earth built in “八”-shaped flat-bottomed trenches, and a pair of rammde-earth bridge-piers on the northern site of the road, near the moat. In the sub-town of the middle Taosi, the foundations of a rammed---earth structure were found to be in the shape of the greater part of a circle with a radius of 22--25m. They must be remains of a three-tier platform. Between the immature-soil core of the platform and the third retaining wall, there are 11 square posts built of rammed earth, with 10 narrow openings kept between. Through each opening a ridge can be seen from the center of the circle. Asimulated survey shows that these openings might have been for observing the sunrise and determining solar terms.
