Changnyongmun Gate, also known as Dongmun, is the eastern gate of Hwaseong. The name refers to the blue dragon of feng shui, which represents the east.
Construction started on May 8, 1795 and was completed only five months later on October 17, 1795. The names of those who were involved with construction are carved into a polished granite wall to left of the structure. All other similar plaques at the fortress have been lost.
The tower, a one story wooden pavilion above the granite base, was destroyed during the Korean War in the early 1950s. It was rebuilt in 1976.