This was the main gate in the fortress wall of Seoul. It is also called Namdaemun (Great South Gate), as it is the southern gate of the capital city. It was first constructed in 1398, and was rebuilt in 1448. The gatehouse, which measures 5 kan (a kan is the interval between pillars) in width and 2 kan in depth, is a wooden structure built in typical style. It is the largest city gate in Korea. There are some conflicting theories about the author of the characters on the plaque hanging from the gate, but it is recorded in an old text called “Jibongyuseol” (1634) that they were written by Prince Yangnyeong.