Tham Pla - Pha Sua National Park is situated in an approximate area of 488 square kilometers or 305,000 rai, covering the areas of Tham Pla - Pha Sua Waterfall in the right hand side of Mae-pai National Conserved Forest, Muang District, and Pang Ma-pha Sub-district. The topography of the National Park consist of high mountains extending northwards, which are the sources of streams and rivers. The natural sightseeing spots at the National Park consist of Tham Pla - Pha Sua Waterfall, which are beautiful and very popular for recreational activities.
The topography of the National Park consist of steep mountains. And Doi Lan is the highest mountaintop of the National Park (1,918 meters above the sea level). The north and the west of the National Park reaches Charn State of the Union of Myanmar; whereas, the south of the National Park reaches Huay Mhak-uen and Huay Peung of Muang District, Mae Hong Son Province; and the east of the National Park reaches the River of Pang Ma-pha Sub-district, Mae Hong Son Province.
The weather at the National Park is influenced by the tropical seasonal monsoon and can be divided into 3 seasons including the rainy season (May-October), when there are heavy rains (within the 10-year period, it rains 138 days/year); winter (November-January), when the weather is dry and cold; and summer (February-May), when the weather is hot and sultry.
There are various kinds of forests within the areas of the National Park, including tropical evergreen forests, virgin forests, pinery, mixed forests, timber forests, and grasslands. Major plants include Lagerstroemia floribunda (Tabaek-na), timbers, Shorea siamensis (Rang), Sindora siamensis Teijsm. Ex Miq. (Maka-tae), teak, Afzelia xylocarpa Roxb., Leguminosae (Pradoo), Xylia xylocarpa (redwood plants), Lagerstroemia calyculata Kurz. (Tabaek-luerd), Malabar ironwood, two-leaf/three-leaf pines, etc.
Wild animals found in the National Park include goral, gaur, wild buffaloes, bears, Muntiacus Muntjak, wild boars, birds, etc.