The park covers parts of Phetchaburi Province and Prachuap Khiri Khan Province. It contains rainforest on the eastern side of the Tenasserim Mountain Range. The highest elevation is 1,20 m. Two main rivers begin within the park: the Pranburi River and the Phetchaburi River. The Phetchaburi is blocked by the Kaeng Krachan Dam at the eastern border of the park. The dam creates a lake covering an area of 46.5 km. The dam was built in 1966. There are private plantations within the park.