Phu Sang National Park is a national park in Northern Thailand. It covers the Thoeng District of Chiang Rai Province and Chiang Kham and Phu Sang Districts of Phayao Province. Phu Sang National Park is located in one of the north-easternmost mountain chains of the Phi Pan Nam Range bordering Laos. The sources of many rivers are in these mountains. The park also has caves with stalactites and stalagmites and a warm water waterfall, Namtok Wang Kaew.
Animals in the park area include the Indian muntjac, the Burmese hare, the Indochinese flying squirrel, black giant squirrel, the Java mouse-deer and the jungle cat.

Source: Wikipedia