- Location 707-15, Guntan-ri, Galmal-eup, Cheorwon-gun, Gangwon-do
Sundam Valley, located about 5 kilometers northwest from Cheorwon-gun Office, is known as the most beautiful valley along the Hantangang River. It is home to many peculiar rocks, cliffs that seem to be carved, ponds, and more. Not only is there a lot of water in the valley, but also fields of rare white sand that forms naturally, making it a popular tourist attraction throughout the year. At the back of the Sundam Valley is the back of the Hantangang river, which is the perfect place for rafting, making it a favorite destination for rafting companions.