Si Phang Nga National Park was designated a national park on the 16th April 1988 (B.E 2531) as the 56th national park of Thailand, with an area of 246.08 km2.

The park is rugged mountain range parallel Andaman Sea coast. The forest on high elevation is fertile for wild life and on the hill is the headwater. Therefore, there are many beautiful waterfalls and cliffs such as Khlong Khu Rot, Khlong Tam Nang, Khlong Phraek Khwa, Khlong Phraek Sai, Khlong Nang Yon, Khlong Bang Wan and Khlong Bang Yai.

The park receive a monsoon weather influenced by southwest and northeast monsoon, it is rain almost the year. As a result, there are 2 seasons: hot season start from January to April; and rainy start from May to December.

The main area is moist evergreen forest, which has Dipterocarpus spp. and Hopea odorata as dominant trees. Moreover, there are herb, bulb plants, moses, fern and other low structure plants. The wildlife, which found abundanly in the forest north of Chiao Lan Dam are Malaya tapir, serow, elephant, barking deer, beer,tiger, lesser mouse deer, gibbon, macaque, langur,banteng, wild boar and birds.