Haeinsa is a Buddhist temple located in the Gaya Mountains of South Korea's Gyeongsang Province. It was founded in 802 AD during the reign of King Aejang of the Silla Kingdom and is known for being home to the Tripitaka Koreana, a collection of Buddhist scriptures that date back to the 13th century.

The temple has a rich history and has been burned down and rebuilt several times throughout its existence. The Tripitaka Koreana was created in response to a Mongol invasion threat, and the wooden printing blocks were carved with a special kind of ink and stored in a special building called the Janggyeong Panjeon, which has protected them from the elements for over 700 years.

Haeinsa is one of the Three Jewels Temples, along with Tongdosa and Songgwangsa, and is considered one of the most important temples in South Korea. The temple complex includes several halls, pagodas, and a museum that displays artifacts related to Korean Buddhism and the history of the temple.

Visitors to Haeinsa can explore the grounds and see the Janggyeong Panjeon, which is a UNESCO World Heritage Site, as well as participate in meditation and other temple activities. The temple is also known for its beautiful natural surroundings, with the nearby Gayasan National Park offering opportunities for hiking and other outdoor activities.