It took sixteen years to complete the Tripitaka Koreana. A copy of the Buddhist scriptures was commissioned by the Korean government (then in exile) in the hope of persuading Buddha to intervene in the crisis caused by the Mongolian Invasion. Over eighty thousand blocks inscribed with nearly seven thousand volumes were made. The wood blocks were made of white birch, a tradition in Korea. The wood is first soaked and then boiled in sea water for three years and then dried in the shade for three years. Once completed the blocks were stored and ingenious techniques were employed to preserve them. The storage unit was built at the highest point of the temple facing southwest to avoid damp south easterly winds and sheltered from the cold north wind by the surrounding mountains. Different sized windows were used for ventilation and to regulate the temperature. Filling the clay floors with charcoal and other moisture absorbing materials reduced the humidity when it rained by absorbing excess moisture. The roof was also made from clay and the bracketing and wooden rafters prevented sudden changes in temperature. No part of the complex was exposed to the sun and animals, insects and birds avoided the area but it is not known why. These preservation measures are deemed responsible for the wooden blocks surviving to this day. Although a modern storage complex was built in 1970 the woodblocks were not moved there as it was discovered they were mildewed. However, the words have now been recorded in electronic form. Note that you can not see what the actual scriptures look like, but you can see the wooden blocks by peering through the slotted windows from the courtyard.