Kaeng Krachan National Park was established in 1981, the 28 th National Park in Thailand. It is the largest national park in Thailand, with 2,914.70 sq.km. of forest in the watersheds of the Phetchaburi and Pranburi rivers. It includes portions of Nong Ya Plong, and Kaeng Krachan districts in Phetchaburi Province and of Hua Hin district in Prachuap Khiri Khan Province.