Ao Phang-Nga National Park was declared a national park on April 29, 1981. It lies in The Mugng Phang-Nga District, Takua Thung and koh Yao District. The park created covers an area of 400 km or roughly 250,000 rai and prodtects the largest area of original primary mangrove forest remaining in Thailand. The park stretches from Muang Phang-Nga District to coast at Takua Thung District. Over 80% of the park is covered by the Andaman sea, with over 42 large and small islands Ao Phang-Nga is national park 25 in Thailand.

              Tham Lod is big cave and length about 50 metres, lies in Takua Thung District. There are beautiful atalactites and stalagmites inside the grotto. During way, you can see a perfect mangrove forest in Thailand.

             You must entrance by canoe only or walking when low tide. the end of cave have a big cavity open to the sky and mangrove forest growing in there.

           A big island and this "Hong" or "room" are collapsed cave system open to sky, filled with jungle of flora and fauna, by the fact, Koh Hong is the favourite place to canoeing.