Formerly, Nam Tok Ngao National Park was called Klong Prao National Park, located in Amphur La-un, Muang, Ranong province; and Amphur Sawee, Thung Tago, Lung Suan, Pa To, Choomporn province. At 668 km2, the park's general geography is rugged mountain range. And it has valuable trees forest and headwaters, suit to set a national park.
The park is a rugged mountain range run north to south, consisting of Khao Daen Khao Huai Siad and Khao Nom Sao that are important headwaters of Ranong and Choomporn
Because of these provinces receive a monsoonal climate; it has heavy rain from May to November. Therefore, the best time to visit there is hot season-from December to April.
Flora and Fauna
There is moist evergreen forest with valuable floras some are Podocarpus neriilolius, Hopea odorata and Michelia champaca. Beside, there is an orchid scattered in deep forest -Dendrobium Formosum, which is similar to Cathalia Orchid and bloom from October to December. Malya tapir, gaur, leopard, beer, barking deer, macaque, wild pig, serow and squirrel are common animals, and "Poo Chao Fah" or princess crab-the crab, which is found here only.