Haeinsa Temple is in Gayasan National Park. It's an old and very important temple in Korea. It's one of three main temples of Chogye Buddhism. The Haeinsa temple represents Dharma (Buddah's teachings). It also contains the Tripitaka. The Tripitaka is a large collection of wooden blocks upon which buddhist scripture is carved. The Tripitaka was first carved in the 11th century but was destroyed by the Mongols during an invasion. The current Tripitaka that is housed in the temple was carved in the 13th century and is made up of 81,340 wooden blocks. It's been designated as an UNESCO World Heritage Site. If you want to read more on this - check out this link. http://en.wikipedia.org/wiki/Tripitaka_Koreana
The temple is quite lively this time of year. Like many temples in Korea it's located inside a National Park. So there were plenty of people that were popping into the temple for a moment before they embarked on a hike.