The whole park covers 645 sq km. It is actually the heart of a complex of five contiguous conservation sites that comprise the largest protected forest on the Thai-Malaysian peninsula, covering over 4,000 sq km. The other sites are Sri Phang-Nga National Park, Khlong Panam National Park, Khlong Saen and Khlong Nakha.
The park is very spectacular with dripping thick native verdant rain forest, punctuated by towering outcrops of limestone cliffs or karsts, waterfalls and sparkling streams, an island studded lake, several caves, and many trails, mostly along rivers.A beautiful large reservoir was created by the construction of the Cheow Lan Dam (also known as the Ratchaprapha Dam) across the Paseang river; this Cheow Lan Lake occupies some 165 sq km. The vast area of water is actually retained by several small dams and the surrounding rock formations are overgrown with lush jungle. Limestone outcrops protruding from the lake can reach heights of 960m, which is three times the height of similar famous formations in Ao Phang-Nga.