Phu Soi Dao can be found in Uttradit Province. It is a mountainous range and the water source of Lan Nam Pao. The weather is chilly all year round with average temperature of 27 Celsius. Phu Soi Dao ranges run north to south and separate the borders between Thailand and Lao. The peak of Phu Soi Dao is 2.102 meters from sea-level. The area is abundant with pine, mountain, rain and pine-dipterocarp forests.