Located between Chongwenmen East Street and Dongbianmen in Dongcheng District, it was built in Yongle in the Ming Dynasty for 17 years and has a history of more than 590 years. It is an integral part of the inner city wall of Beijing, the only remaining section and the symbol of Beijing. Its southeast corner building was built in the first year of Ming Dynasty orthodoxy, and it is a national key cultural relic protection unit.