Originally named the Heungguksa Temple, the Gaemoksa Temple was built by one of the greatest Buddhist monks of Silla named Uisang during the reign of King Sinmun (ruled from 681 to 692). According to a legend, Uisang decided to build this temple after being spiritually awakened inside the Cheondeunggul Cave right behind the temple site with the help of a celestial maiden. Records show that the name was changed to the 'Gaemoksa Temple' during the Joseon Dynasty. The Wontongjeon Hall housing the statue of Avalokitesvara Bodhisattva is believed to have been built in 1457 (3rd year of the reign of King Sejo) because of a written record found during the reconstruction in 1969, which says ‘The First Year of Joseon Conforming with God’. It measures three kan (a unit of measurement referring to the distance between two columns) in the front and side each. The structure is under a gable roof. Brackets are placed on the poles to support the roof. The front and back of building are differently shaped. The ceiling inside the building is a lotus lamp ceiling transparent enough to make the rafter visible. And the inside of Buddhist sanctum has an Ondol (a traditional heating system in Korea), which is very rare in the early Joseon Dynasty. The whole building is built sturdy and the construction materials show the unique architectural characteristics of the early Joseon Dynasty. It serves as an important source for the study of the history of Korean architecture.