The history of Yeosu Aeyangwon, a leprosarium, began in 1909 with an American medical missionary named Wiley H. Forsythe who initially opened the institution for ten or so patients. Having relocated from Gwangju to Yeosu in 1927, it was first called the Biederwolf Leper Colony. Its name was changed to Aeyangwon in 1935. In 1972 it was remodeled into a nursing home but was then neglected until 2000 when the Yeosu Hospital reopened it as the Yeosu Aeyangwon History Museum. YÉOL has supported the cataloguing and translation of the Aeyangwon archives, which include medical tools from the early modern period and records of missionary work.

The Ulju Bangudae Petroglyphs are a series of prehistoric rock engravings that stands 3 meters tall and 10 meters wide. They depict images of whales, deer, tigers, wild boars and other assorted animals in addition to boats, harpoons, fishing nets, and humans. They were first discovered in 1971 and was designated National Treasure No. 285 in 1995. The rock cliff on which the engravings are carved is submerged for half the year due to the nearby Sayeon Dam, which was built before the petroglyphs were discovered. The repetitive rise and fall of water levels have eroded the petroglyphs to the point that they are in dire need of preservative measures. YÉOL has supported efforts by historians to preserve the petroglyphs.