The gate, dating back to the 14th century, is a historic pagoda-style gateway, and is designated as the first National Treasure of South Korea.

[2] It was once one of the three major gateways through Seoul's city walls which had a stone circuit of 18.2 kilometres (11.3 mi) and stood up to 6.1 metres (20 ft) high.

The South Korean government, as written in hanja on the wooden structure, officially calls the landmark Sungnyemun,[3] even though it has been more commonly known as Namdaemun since the Joseon period.

A common belief in Korea is that the name "Namdaemun" was imposed forcibly during the Japanese colonial period, and therefore should not be used.

However, Joseon dynasty annals indicate that naming the eight gates of Seoul after their respective directions was common colloquial usage before the Japanese arrived.

In the early part of the 20th century, the city walls that surrounded Seoul were demolished to make the traffic system more efficient.

At approximately 8:50 p.m. on 10 February 2008, a fire broke out and severely damaged the wooden structure at the top of the Namdaemun gate.

[17][18][19] A police captain reported that Chae had sprayed paint thinner on the floor of the structure and then set fire to it.

[21] On 25 April 2008, Chae was convicted and sentenced to ten years' imprisonment by the Seoul Central District Court.

[24] President Lee Myung-bak proposed starting a private donation campaign to finance the restoration of the structure.

The pillars and rafters are to be elaborately decorated, with the ornamental patterns and colors based on those used in the large-scale repair in 1963, which was closest to the early-Chosun original.