Among the DPRK’s natural monuments is the Ninety-Nine Curves of the Chonsang Stream in Sampho-ri, Yonsa County, North Hamgyong Province.
The Ninety-Nine Curves are located in the valley through which the Chonsang Stream flows as a tributary of the Yonmyon River rising from Kwanmo Peak of the Hamgyong Mountains.
The stream flows in a high place, hence the name Chonsang, and the Ninety-Nine Curves point to a large number of rocky curves in the stream.
The unusual valley in the highlands was designated as a natural monument as it is useful in studying crustal movements and topography.
Bedrocks at the bottom and both sides of the curves were formed by the unique texture of granite.
In the rainy season, the stream runs down swiftly with roaring sound and, in the dry season, round stones are exposed in the air.
The stream is 4 to 18 metres wide, 3 to 10 metres deep (over 10 metres at the deepest) and 18 km long (16 km in a beeline).
The stream is of great scientific significance.