Jungyangmun Gate was built in 1790 by King Jungjo. It is also known as Naesammun Gate, which literally means "three gates on the inside," it serves to protect the immediate vicinity of Bongsudang, the central court of Hanggung Palace. The name ‘Jungyang’ is derived from the village where Gojo Yubang resided during the Han Dynasty, a name chosen by King Jungjo. Initially named ‘Jungyakmun,’ the gate underwent a name change when it was relocated to the front of the Wuhwagwan. Jungyangmun Gate comprises the central gate, Wuhyup Gate, and Jwahyup Gate on its sides. Moreover, a lengthy Haenggaek was constructed on both the left and right sides of the gate to regulate access.

In 1795, Queen Heonyeong's (Hyegyeonggung Hong) 60th birthday celebration, known as Jinchanrye, was hosted at Jungyangmun Gate in front of Bongsudang. King Jungjo, along with other royal relatives and ministers, graced the occasion.