The Ogasan Nature Reserve is situated in the dense forests in Karim-ri of Hwaphyong County, Jagang Province. Here grows a 1 100-year-old yew tree.

   The 16.5m-high tree is 4.1m round at the root neck, 3.6m round at the chest height and 7m across at the crown.

   It is oval in shape and its branches stretch almost horizontally; lower ones grow a bit downward and the upper ones upward.

   Its trunk with deep grooves is characterized by getting twisted upward.

   As the tallest and oldest yew in the country, the tree is a valuable treasure which shows the natural history of Mt Oga, as well as a natural monument of great importance for scientific research.