Daehanmun Gate is the main gate of Deoksugung Palace. Its original name was “Daeanmun Gate,” which means “national prosperity and welfare of the people”. It earned its current name in 1906, which contains the meaning “Hanyang (today’s Seoul) will prosper."

The main gates of the royal palaces were usually located in the south. Although Daehanmun Gate serves as the main gate today, the original main gate of Deoksugung Palace was Inhwamun Gate, which faced the south. However, Daehanmun Gate became the primary entrance due to its increased use and the narrowness of the road in front of Inhwamun Gate.

Like the main gate of Changgyeonggung Palace, Daehanmun Gate also faces the east. It is the only one-story main gate that consists of three entrances and two sections from the side. It has a hipped and gabled roof with eaves supported by multi-cluster brackets. The base and stairs of the gate are already buried underground.

Daehanmun Gate was not always located where it is now. It used to be located about 33 meters away from the current location. During the Japanese colonial period, the surrounding roads were greatly expanded, and it had to move westward from its original position. The expanded road took up a large part of the east of Deoksugung Palace. After the liberation from Japanese colonial rule, due to the second road expansion construction, the wall of the palace was moved further backwards, and Daehanmun Gate was left lonely in the middle of the road for a period of time before being relocated to the current site in 1970.