Oeosa Temple in Unjesan Mountain is a place where the deep scent of Buddha can be felt with a lake that looks like a dragon wrapped around it and the strangely-shaped cliffs which harmonizes like an oriental painting. Oeosa Temple is a sacred place where the four great patriarchs of Silla were born. This temple was built during the reign of King Jinpyeong (579-632), the 26th ruler of Silla. It was originally called Hangsasa Temple, but when Great Master Wonhyo and Zen Master Hyegong practiced religious asceticism here, a contest was held to revive the fish in the stream with religious power. However, one of them did not survive, and the other did and swam vigorously.
So each argued that he himself saved the fish, so they called it Oeosa Temple by writing the characters 'O' and 'Eo.' Daeungjeon Hall has a hip-and-gable roof with three bays in the front and two in the side. It was rebuilt in the 17th year of King Yeongjo of the Joseon dynasty (1741). Around the temple, the beautiful natural scenery of Unjesan Mountain and the blue water of Oeoji are spectacular. Jajangam Hermitage can be seen on the rocky cliff, and Wonhyoam Hermitage can be seen to the west of Oeosa Temple. Daeungjeon Hall (Gyeongbuk cultural heritage) has a national treasure bell, Buddhist monk Wonhyo's hat, and many other relics.