Situated in South Thailand, Khao Sok was established as Thailand's 22nd national park in 1980 by The Royal Forest Department. The park covers 739 km² land area of Amphoe Phanom and Ban Takhun in Surat Thani province and includes the Cheow Lan reservoir dammed by the Ratchaprapha dam. The relatively convenient distance to Koh Samui, Phuket, Krabi and Khao Lak makes this park the most popular national park in South Thailand.