On the Erlitou site, a palace-city and a network of roads in its periphery have been discovered in recent years. The main road functioned continuously from the early to the late stage of Erlitou culture. The palace-city has a plan in the shape of a vertical rectangle and occupies an area of about 108,000 sq m. It was built at the turn from the second to the third phase of the Erlitou culture and existed to the fourth phase or a little later. This is the remains of the earliest palace-city known so far in China. Among the other important findings are wheel tracks of the early Erlitou culture and turquoise-containiing waist pits of the late Erlitou. The discovery of the palace-city and road network suggests that the Erlitou site is left over from a city large in size and neat in layout.
Building Foundation No. 4 of the Erlitou site is located in the eastern palace-area,straight ahead of Palace-foundation No. 2. Its main part was excavated from the spring of 2002 to the spring of 2003. These remains consist of the rammed-earth platform of the main pavilion and the vestiges of the eastern corridor, with the former occupying an area of over 460 sq m. Judging from the discovered vestiges, the fourth foundation can be reconstructed to represent a building complex formed of the main pavilion, the eastern and western corridors and the yard between them. These buildings were constructed in the third phase of Erlitou culture, roughly simultaneously with the complex represented by Foundation 2. The two compounds shared the same central axis and must have belonged to the same building group.