Huay Sai Waterfall is an extraordinarily beautiful waterfall, especially during the late rainy season when water flow is abundant. This makes it an ideal destination for travelers. Huay Sai Waterfall is formed by the Sanam Sai stream, which originates from the lush rainforest of Dong Naeng, flowing through the Sam Phak Khao Forest. This stream serves as a natural boundary between Nam Nao District in Phetchabun Province and Khon Sarn District in Chaiyaphum Province.