Kaeng Krachan was declared as a national park on 12 June 1981. Covering an area of 2914 km² it is the largest national park in Thailand. The park is located in Phetchaburi and Prachuap Khiri Khan Provinces, bounded by the Tanintharyi Nature Reserve along Myanmar's border to the west. The park is not only part of the rainforest area north and south of the park in Thailand, but also part of the Western Forex Complex that covers 18,730 km² across 19 protected sites between Myanmar and Thailand.

Kaeng Krachan National Park is famous it's diverse wildlife, but also for the dense morning mist covering the park with hill tops sticking above mist cloud around December-March, creating a spectacular view.