Introduction to the Southeast Corner Tower: The Corner Tower was the archery tower at the southeast corner of the inner city of Beijing during the Ming and Qing dynasties, referred to as the Corner Tower. Beijing was originally divided into inner and outer cities. The inner city was built earlier and was rebuilt by the Ming Dynasty on the basis of the Yuan Dynasty. The corner tower was built in October of the first year of the Ming Dynasty (1436) and has a history of more than 500 years. The southeast corner tower is the largest remaining city wall corner tower in the country and is a national key cultural relic protection unit.