Yongcheng, a site located in Fengxiang district of Baoji city, Shaanxi province, was once the capital of the Qin State from the middle Spring and Autumn Period (770-476 BC) to the early Warring States Period (475-221 BC).
In 2022, archeologists excavated the Wayaotou architecture site, situated in the eastern area of Yongcheng, unearthing a vast archeological complex consisting of more than 500 building materials and other items dating back to the Spring and Autumn Period.
Grey clay building materials, such as flat roof tiles, cylinder roof tiles, and semicircular tile ends, were discovered, adorned with numerous engraved symbols.