Gyeongbokgung, historic site 117, was the primary palace of the Joseon Dynasty. This building is Gyeonghoeru and is where official banquets were held and foreign envoys entertained. The guide flyer I have says this:
There was a small pavillion when Gyeongbokgung was built. King Taejong dug the pond and rebuilt this pavilion to its grandeur in 1412. It was burnt down during the Japanese Invasion of 1592 and restored in the 4th year of King Gojong (1867). This is the best example of Joseon time’s pavillion which has 48 granite pillars. It shows [the] highly advanced architecture of [the] Joseon period.
There was some kind of cleaning work going on in the pond, so getting shots of the pavillion without plastic fences in the water was a little challenging.