Tuan Cheng Fortress, Military museum at Haidian District, China

Tuan Cheng Fortress is a circular military compound in Haidian District featuring defensive walls, gates, and towers. The structure follows traditional Chinese military architecture principles and spans extensive grounds near the Fragrant Hills.

The compound was built in 1749 during Emperor Qianlong's reign as a training ground for Qing troops. It played an important role in the military infrastructure of the Chinese imperial system of that era.

The fortress displays military artifacts and ancient weapons from different periods. Visitors can learn about the role this site played in imperial defense strategies.

The site lies 1 km southeast of Fragrant Hills Park in Haidian District. Two ramps inside the oval wall lead to the top of the 10-metre ramparts, which have arrow parapets. The drill hall, gate tower and stele pavilion stand in sequence from south to north.

The compound's name means "Round Wall Fortress" because its wall forms an oval 50.2 m east-west and 40 m north-south, 10 m high and 5 m thick. Both gate plaques are in the Qianlong Emperor's own hand: "威宣壁垒" on the south gate and "志喻金汤" on the north.