The introduction of the rubber tree at the beginning of this century, the oil palm in the seventies and the rapidly growing population over the last 50 years were the main reasons for the widespread destruction of the rain forests all over Thailand.

The remarkable exception to this devastation is the extensive system of national parks, wildlife sanctuaries and other protected areas, that has been established over the past forty years. Different from other nations, where national parks have been established several decades ago, for Thailand, they are a recent development: the first, Khao Yai, was established in 1961. Today, almost all of Thailand's remaining natural forests, together with most of its wildlife, are located in protected areas. Included in this treasure are some of the last great forests of mainland Southeast Asia and some marine habitats in the Gulf of Thailand and the Andaman Sea.

The laws, that regulate the protected areas of Thailand, state that areas, declared a national park should be of natural interest and should be preserved in its natural state, while wildlife sanctuaries are set aside for the conservation of wildlife habitat. Non-hunting areas and forest parks have similar management aims and can be upgraded if considered appropriate.

Wildlife sanctuaries are not generally open to visitors although scientists can conduct research within their boundaries. Some adjoin national parks and allow wildlife a greater roaming range and corridors to facilitate breeding. Together, these protected areas cover 65,534 square kilometres or 12.8% of Thailand, one of the highest ratios of protected area to total country area in the world.

Visitors who are aware of the definition of a national park may be astonished, when they visit places like Phi Phi Island or Khao Yai, where hotels have been built by private entrepreneurs, villages by hill-tribes or "strategic" roads by influential people to allow year round access to the remoter areas.

Every year fires destroy valuable park areas and poaching and encroachment exist in almost every protected area in Thailand. Illegal loggers cross the inadequately defined and poorly guarded park boundaries, squatters plant cassava, jute and other crops and villagers hunt animals and gather sap from trees by hollowing out their trunks with fire.