Oksanseowon Confucian Academy was constructed in 1572, the fifth year of King Seonjo of the Chosun Dynasty, in honor of Lee Eon-Jeok, one of the great Confucian scholars of the Chosun Dynasty and one of the Five Great Wise Men of the East (his pen name was Hoejae). Neo-Confucians divide all existence into two inseparable components, i and ki(li and chi in Chinese) The one, i, is a patterning of a formative element that accounts for what things are and how they behave or normatively should behave, while the other , ki, is the concretizing and energizing element. The pioneering thinker in the school that stressed the primacy of i was Lee Eon-Jeok.  The academy is set against a backdrop of Mt. Jaoksan, Mt. Dodeoksan, Mt. Hwagaesan, Mt. Muhaksan and five rocks including Jeungsimdae, Gwaneodae and Sesimdae. This famous institute is larger than 100 kan (kan is a traditional unit of measure referring to the space between two columns).  Amsujae Library at Oksanseowon houses a total of 4,111 volumes of 866 different titles, including Samguk -sagi (The History of the Three Kingdoms), designated as Treasure No. 525.