Sungnimun Gate is one of the four major historical gates in Seoul. It was designated National Treasure No. 1 by the Korean government in 1962. Although its official name is Sungnimun Gate, it is also known as Namdaemun Gate due to its location at the end of the South of Seoul, and with the passage of time, the city of Seoul grew in size but the gate remained in its original location through the ages. Construction of the gate began in 1395 and was completed in 1398. In 1447, it underwent a series of reconstruction works. Today it is the largest gate in the city with its arched entrance, and above its wooden base stands a two-story wooden structure, the oldest wooden structure in Seoul.