The Site is situated within Mudeungsan National Park, a mountainous national park formed by volcanic activity. The geology of the upper basin ensures that the downstream wetlands are supplied with clean water at a consistent temperature year-round. The Site was once rice paddy fields, but following natural restoration, its mountainous marshes have recovered, with the willows Salix koreensis and Salix glandulosa as the dominant tree species. The wetlands provide habitat for at least 578 species, which notably include rare plants such as Semiaquilegia adoxoides, Lysimachia barystachys and Gynostemma pentaphyllum, the nationally endangered Eurasian otter (Lutra lutra), yellow-throated marten (Martes flavigula) and mainland leopard cat (Prionailurus bengalensis), and the insect species Agrypnia pagetana which is nationally vulnerable. The Site also supports eight species of amphibians, including the largest population of Ueno’s brown frog (Rana uenoi) of all the Republic of Korea’s national parks. This species is also listed as a national indicator species for climate change. The invasive plants Ambrosia artemisiifolia and Humulus japonicus may disturb the wetland ecosystems and are being managed. Alongside its importance for biodiversity and nutrient cycling, the Site supports recreation, tourism, and scientific and educational activities.