The term "Xizhimen" means western axis gate and is located along the northern section of the Inner City western wall. In 1419, the area was changed to reflect its location. Built on the site of a famous Yuan Dynasty-era gate called ‘Heyimen,’ the gate tower and the watchtower are similar to that of Dongzhimen. The gate tower was 32 meters long and15.6 meters wide. The actual height is 32.75 meters.

The barbican is 68 meters by 62 meters, with a sluice gate and an archway on its southern side. Its Guandi Temple, which was dismantled in 1930, is located at the northeastern corner and faces South. Heyimen's barbican was built during the reign of Yuan Shundi, in 1360.

The area has been frequented by citizens for more than 60 years since the Ming dynasty. During the Zhengtong era (1435–1449), at a time when the other Inner City gates were all undergoing complete reconstruction. During this time, it was covered over with bricks and was merged with the new watchtower platform.

Due to a lack of sufficient fresh water in Beijing, the Imperial family and wealthy families would get their water from springs on Mount Yuquan in the northwestern suburbs. Every morning, carts carrying spring water would enter the city through Xizhimen. Thus, a symbol of water is engraved on the barbican gate archway of Xizhimen.

Xizhimen, which remains the last gate to remain fully intact, was completely dismantled in 1969. During the demolition, workers discovered that parts of the barbican gate's archway, had been there since the thirteenth century. It remains among China’s national historical heritage sites today.