A district administration office for Gwangju was moved to Namhan Mountain Fortress upon its completion, establishing its status as a functioning fortress. In addition, a temporary palace (行宮 Haenggung) was completed below the West Command Post in the 9th moon of 1624, while the fortress walls were being built.
This palace compound, which was known as either Gwangju Haengung or Namhan Haenggung, consists of two sections, upper and lower. Important structures on the site included Jwajeon (左殿 Left Hall), Usil (右室 Right Hall), Jaedeokdang (在德堂 Hall in Virtue), Hannamnu (漢南樓 Hannam Pavilion) and Inhwagwan (人和館 Human Harmony Guesthouse). The compound, fit for the residence of a king, had a total of 227 compartments, or kan (間 unit for the space enclosed by four pillars). The upper section consisted of 73 kans, while the lower section had 154. "Haenggung" (行宮 travel palace), or "Haengjaeso" (行在所 a place to stay when traveling), refers to a place where the king could rest while outside the capital. King Injo resided here for 47 days (14th day of the 12th moon, 1636 until the 30th day of the 1st moon, 1637) during the Manchu Invasion. Kings Sukjong, Yeongjo and Jeongjo also stayed here while on trips to royal tombs to perform sacrifices. As such, this temporary palace compound played a more important role in history than other compounds of its type did.
The royal compound at Namhansanseong had 18 buildings and a total of 33 structures when including various gates and so on. The buildings can be classified according to purpose: the temporary palace halls, the "left-side hall," and the local administration halls.
Temporary Palace Halls (Naehaengjeon, Oehaengjeon and Hannamnu)
The Naehaengjeon (內行殿 Inner Palace Hall) was the king's quarters and measured seven kans (bays) wide by four kans (bays) deep for a total of 28 compartments. The three kan in the center served as a large, open floor that was unheated. Rooms equipped with ondol floor heating were on each side, and a narrow wooden veranda was built around the sides and rear of the outer rooms. This was a standard floor plan for a royal residence, and was also applied at Tongmyeongjeon, Hwangyeongjeon and Gyeongchunjeon at Changgyeonggung (Palace) in Seoul. However, the Changgyeonggung royal quarters are depicted in the Painting of the Eastern Palaces (東闕圖 a detailed aerial view of Changdeokgung and Changgyeonggung produced between 1826 and 1830) as being in open surroundings. They have "false verandas" (假退) on their foundation platforms, providing space where bodyguards could be posted. On the other hand, the residential quarters at Namhan Mountain Fortress were more enclosed. The hall was surrounded by a wall, and the auxiliary facilities were outside that wall.
Oehaengjeon was the main building in the lower (or outer) section of the compound, which means it served as a temporary main throne hall. It measures 7 kans across by 4 kans deep, for a total of 28 bays, the same number that Naehaengjeon has. However, Oehaengjeon is somewhat smaller in area. The total floor space of the inner private hall is 167m2, while that for the outer public hall is just 142m2, which affords it a lower status. The multi-cluster columnar brackets (栱包), too, are without the protruding "beaks" that are typically found on a main throne hall. Hannamnu was built in 1789 under the order of Gwangju Special Mayor Hong Eok. The two-story pavilion is at the entrance to the temporary palace compound and measures 3 kans wide by 2 kans deep. Traditionally, a person is supposed to pass through three entranceways before reaching the main throne hall. Before the construction of Hannamnu, only two gates were in front of Oehaengjeon. The addition of Hannamnu, with large doors on the first floor, made up for this discrepancy.
The Left-side Hall (Royal Ancestral Shrine)
The main axis aligning the layout of the temporary palace faces east, following the natural terrain. However, Jwajeon (左殿 Left-side Hall), an ancestral shrine, is positioned according to ritual propriety, facing south at the foot of a hill situated north of the temporary palace compound. The building is 5 kans wide by 3 kans deep, but the front and rear bay rows of are fashioned as verandas, so the floor layout consists of just ten bays in total. The reason for the name "left" is not known for certain. Some contend it denotes that the structure was intended to serve as a detached palace or detached hall. Indeed, the hall for enshrining the spirit tablets or images of royal ancestors is located to the left of the temporary palace. However, the term jwa (left) also has a ritual meaning of "grave," and the word jeon (hall) was attached to it. Jwajeon (the shrine to the royal ancestors), along with Usil (a shrine to the state deities), were symbolically important and made Namhan Mountain Fortress stand out among the rest of the temporary palaces from Joseon. In times of emergency, the fortress was meant to serve as a temporary capital for the entire kingdom, and these halls legitimized that role. Unfortunately, the site where Usil once stood was used as a collecting pond and become badly damaged. Plans call for a reconstruction of the shrine in the future.
Local Administration Halls (Jwaseungdang, Iljanggak and Inhwagwan)
Jwaseungdang (坐勝堂 Sit-and-Win Hall) and Iljanggak (日長閣 Daylong Hall) were both constructed during the reign of King Sunjo as offices for the Magistrate of Gwangju. Jwaseungdang was completed in 1817 under the direction of Special Mayor Sim Sang-gyu and measures 6 kans wide by 2.5 kan deep. Special Mayor Yi Ji-yeon had Iljanggak built 12 years later, in 1829. This structure was 4 kans wide and 3 kans deep, with the front and back bay rows fashioned as verandas. Thus the total floor space was just 8 kans. The name Jwaseung-dang implies that one can be victorious without fighting. The hall was built in 1817, marking 180 years (three 60-year cycles according to the traditional calendar) since Joseon capitulated to Qing. Inhwagwan was constructed as a guesthouse under the orders of County Magistrate Yu Rim in 1624, when the town administration office was moved to the fortress site. The structure had 68 kans in total floor space. Traditionally, the royal guesthouses were located in the center of a provincial district. Tablets symbolizing the king (殿牌) and king's palace (闕牌) were enshrined here. The tablets were brought out on the 1st and 15th of each lunar month, and local scholars and government officials would hold a ceremony to show their respect, bowing in the direction of the capital. "Wing halls" (翼軒) were located on each side of the guesthouse to provide lodging for traveling dignitaries.