Wanping Fortress, also known as Wanping Castle, is a Ming Dynasty fortress or "walled city" in Beijing. It was erected in 1638–1640, with the purpose of defending Beijing against Li Zicheng and the peasant uprising.
The fortress has two gates: the east gate, named Ever Prosperous Gate (永昌门, Yongchangmen), then renamed as Majestic Gate (威严门), and the west gate, named Favorably Govern Gate (顺治门, Shunzhimen).
In Chinese, the fortress is sometimes called Wanping City, and from the beginning, it functioned as a military fortress. From west to east, it measures 640 metres (2,100 ft), and from south to the north 320 metres (1,050 ft), making it a half-square shape.
The Museum of the War of Chinese People's Resistance Against Japanese Aggression, surrounded by a plaza and park with numerous sculptures, occupies a large portion of the space inside the fortress' walls.
To the west of the fortress are the Yongding River and the Lugou Bridge (Marco Polo Bridge, 卢沟桥).