Mt Oga was derived from five scenic peaks with the height of over 1 000 meters towering above a primeval forest.

The Ogasan Nature Reserve covers over 6 500 hectares of forest surrounding Mt Oga, in which there are a number of precious natural monuments like 800 hectares of virgin forest.

The reserve draws worldwide attention, as it is one of the oldest forest areas in Korea with 1 330 species of animals and plants and has the virgin forest that cannot be seen in other famous mountains.

In the reserve, there are many trees that have grown for over hundreds or a thousand years, like 1 100 year-old yew, 700 year-old Mongolian oak and 500 year-old pine-nut tree and linden.

It is also abundant in medicinal and edible herbs, including forest asiabell, barrenwort, mountain peony, Aralia elata, bracken and anise, and serves as a good habitat for hundreds species of wild animals, birds, batrachians, reptiles and fishes.

The Ogasan Nature Reserve is of great significance in academic research and dissemination of science and knowledge. Its biology is getting richer thanks to the correct nature conservation policy of the Workers' Party of Korea and the DPRK government.

President Kim Il Sung and leader Kim Jong Il in their lifetime underscored the need to protect the nature of picturesque Mt Oga on several occasions.