It is a valley located in Yongdae 1-ri, Buk-myeon, 12km away on National Highway 46 between Inje Goseong. In a series of waterfalls and baths, bead-like blue water flows with all kinds of changes and tricks with a roar like thunder. In the olden days, the 12 baths and 12 baths were commonly called the Twelve Seonnyeotangs, and the shape of the baths was formed by the rough river bed over a long period of time, forming strange and amazing shapes such as concave or the rocks forming wide and deep holes. The valley leading to Twelve Seonnyeotang is covered with large trees such as maple trees, fir trees, birch trees, and pine trees, making the view of the valley truly enchanting. Twelve Seonnyeotang Valley has many iron bridges across the water, but since it is a typical V-shaped valley, it is said that it is not recommended to go upstream in case of heavy rain.

Not many people visit this valley all year round except during the fall foliage season. If you follow the information board from the top of the valley to Daeseungryeong, you must be careful because the terrain is easy to confuse. It is also a good idea to prepare a compass and a map, especially when it is foggy or rainy, as it is common to take the wrong route. It takes 7 hours and 30 minutes to 8 hours of walking time to climb from Namgyo-ri to the Twelve Seonnyeotang Valley and down to Jangsu-daero via Daeseungnyeong. The same goes for starting from Jangsu-dae, passing through Daeseungryeong, and coming down to the Twelve Seonnyeotang Valley. Taking breaks and meal times in between, it should take at least 10 hours. Since there are no mountain huts or shelters along the way, most people start from Namgyo-ri early in the morning and complete the hike all the way to Jangsu-dae in one day.