Gayasan National Park, National park with mountain peaks in South Gyeongsang, South Korea

Gayasan National Park covers over 160 square kilometres of the Sobaek range, from the northern edge of South Gyeongsang to the southern limit of North Gyeongsang. Its two main peaks are Sangwangbong at 1,430 m and the slightly higher Chulbulbong at 1,433 m. Haeinsa, a principal temple of the Jogye Order, stands within the park, whose slopes hold Yongmun Falls and Hongnyudong Valley.

The area was designated Scenic Site No. 5 on 24 June 1966, covering Gayasan and Haeinsa, and became South Korea's ninth national park on 13 October 1972. A park management office opened in 1974, and the National Park Management Corporation took over in 1987. Its remoteness spared it from destruction during the Japanese invasions of 1592–98.

Haeinsa belongs to the Jogye Order, the main school of Korean Buddhism, and is one of its principal temples. Its grounds hold a standing Buddha figure carved into a vertical rock face, which visitors can see while walking the temple area. The temple sits on Gaya Mountain, from which the park takes its name.

The most used trail starts at Haeinsa Temple, where a guard station gives park information to visitors. Three designated campgrounds inside the park serve day use and overnight tent camping. The park stretches from the northern edge of South Gyeongsang Province to the southern limit of North Gyeongsang Province.

Haeinsa's Janggyeong Panjeon, the halls that hold the Tripitaka Koreana, stand within the park; the temple is one of the main centres of the Jogye Order of Korean Buddhism. The 13th-century woodblocks number over 80,000 and are carved on both sides.