Formerly, it was a national conservation forest namely Wang Duan forest and Huai Yang forest, after that forest department defined policy to establish a national park and transfered this area to be look after by the national park Division which including sea and two islands : Ko Chan and Ko Thai si, covers area about 38 square kilometers This 76th national park establisment is effective on December 30, 1992.

Topography
It's a plain area paralleling with a sea coast. At the level of 0 - 5 meters above the mean sea level is a long beach lying from north to south. This beach is very clean and beautiful which many tourits who love to visit.

Climate
Generally, It is a monsoon hot climate and be influenced by sea wind. The raining season and hot or dry season would be different. Raining season starts from May to November while the winter season starts from December to January and February, April is the hot season. There is the highest raining water in October while in December is the lowest.

Flora and Fauna

Vegetation
Forest resource in the Had Wanakorn National Park is the mixed forest and generally, it's tall forest consists of bamboo, mikey tree, yang na, oramosia and pterocarpus. The former forest in the Had Wanakorn National Park is the replenished forest mixed together with recovered natural forest and replanted tree such as myrtle and lagerstroemia etc.

Wild Animals
Wild animals were founded totally 61 types, many are edible-nest swiftlet, other wild animals are birds totally 48 types, and other kinds of 13 wildlifes such as jungle fowl, squirrel, treeshrew, lepus pequensis, skink, canis aureus, shake and porcupine etc.

Sea Resources
There are a lot of aquatic animals such as shrimp, fish, coral, turtle some kinds of dolphin. In addition, around Chan island and Tai Tsea island, there is some beautiful coral reef and in the ocean also found the source of sea grass e.g. phom nang grass. While some rock area and plain along a beach is the natural place for incubating and growing of mussels.