The Ongnyonsan Stone River is located in the upper reaches of the valley in the southwestern slope of Mt Ongnyon in Pujon County, South Hamgyong Province.
Mt Ongnyon rises 2 164m above sea level in the southern tip of the Puksubaek Mountains stretching along the meridian line on the Kaema Plateau.
In general, a stone river or stone sea is a unique landform which came into being when masses of rocks on the outskirts of glaciers fell down to the valley floor. The same is the case with the Ongnyonsan Stone River, which is the biggest and rarest stone river in the country.
The stone river, 120m wide and 700m long, shows the wonder of nature.
It has a gradient of about 10 degrees. Water is invisible as it flows under the stones, but the sound of running water is heard.
Stones are piled up 4-5m thick on average and 15-20m thick at the bed of the valley.
The edges of stones were weathered into irregular shapes with different cubic or plate sizes.
The stone river has been designated as a natural monument as it adds beauty to the scenery of the mountain and is of academic significance in studying mountain glacier.
Kim Kyong Hyok
Comprehensive Service Centre for Leisure Activities and Medical Treatment
The Onpho Working People’s Holiday Camp was inaugurated with due ceremony on January 20. The holiday camp built in a scenic
February 19, 2026
The Onpho Working People’s Holiday Camp was inaugurated with due ceremony on January 20. The holiday camp built in a scenic
