Laemson National Park is situated on the Andaman sea coast in Ranong and Phangnga provinces. It consists of approximately 60km of coastline and 15 islands. The park was established on 19th August 1983 by royal decree. The park covers a total area of 315 sq.km, of this area 85% is open water. The park is the 12th Marine National Park of Thailand and is its 6th largest.

The coastal section stretches from Ao Ang Mountain (264m) in the North to Pak Triam Mountain (155m) in the South. The coastal section of the park extands inland about 2km, but in several places stretches no further than high water mark. All the parks islands are situated nearshore, the furthest being 12km offshore. These islands are unspoilt with no permanent habitation although they occasionally act as a refuge for fishing boats during monsoon storms.

Coastal Environment, The sea around the islands and offshore is rich in marine life with many habitats present including; coral reefs, open water, seagrass beds, mangrove swamp, estuarine and beach. The park includes some very important nursery grounds for economically important species. There preservation ensuring continued supply in the Andaman sea offshore fisheries. Due to the proximity of the shore the water in the park is very often turbid with sediment thus restricting coral growth to a few locations in the park. The best coral occurs at the northern end of Kam Archipelago, but these reefs are very stunted compared to the corals present offshore at nearby Mu Ko Surin National Park.

The landscape is rocky of kang krajarn in the tanaosri rocky group. The shore area of the national park is notched and deep sea, not very far from the shore it is just like a sinking area, thus all along the sea sides are quite narrow with quite a number of small short streams from the upper inland flow out to the Andaman sea. These rivers and canals have cumulated some dirts at the estuary and sea shores, thus the areas along the sea shores nearby the estuary area and the canals are covered up with mangrove forest. Areas next to the opened sea, the shores are quite muddy and sometimes dunes might be found during low tide.

The weather conditions are hot and humid, high humidity. There are 2 seasons, rainy and summer, it making the climate cool all year round. Ranong is the famous of rainy, and also called is “ 8 months rainy and 4 months summer district” , the rainfall is more than 4,000 millimeters. Rainy is started from April to November, and June to September is the famous of rainy, so the rain fall is more than 700 millimeters per month. The summer is from December to mid April is the most appropriate season for travel

The principle terrestrial habitat at Laemson National park is the extensive Mangrove forests. Approximately half of the coastal area of the park is covered by mangrove forest which accounts approximately 14 sq.km. The most extensive areas occur around Laem Kluai, around the Thao Island, behind the beach on the coast opposite Kam Nui Archipelago and at the northern end of the park around Ao Ang Aountain. In some patches the mangrove forest extends across the park boundary to link with extensive areas outside the park. In these locations the forest is quite unspoilt with high species density.

The mangrove forest at Laemson is zoned depending upon its proximity to the sea. The landward side is dominated by Rhizophora and Bruguiera species especially; R. mucronata, R. apiculata, B. gymnorrhiza, B. parviflora and B. cylindrica, also occuring are Xylocarpus granatum, X. moluccensis and Acanthus ilicifolius. The seaward side is dominated by the pioneer species Sonneratia alba, Avicennia alba, Ceriops tagal, Acanthus ilicifolius and A. volubilis.

Along the coast above high water mark and fringing the islands are areas of beach forest. The dominant tree species is the pine Cassurina equisetifolia which provides shade and ventilation, thus the ideal place to relax or picnic. Other trees found here include; Barringtonia asiatica, Terminalia catappa and Derris indica.

Inland on the larger islands; Kam Yai Archipelago, Kam Nui Archipelago, and Piak Nam Noi Island and on the slopes of Ao Ang Mountain, Bang Ben Mountain, and Pak Triam Mountains small patches of tropical evergreen forest occur. This forest has been greatly influenced by human activity, with trees selectively felled especially for boat building

In locations where human impact has occured and trees have been felled patches of grassland are present. Grassland now covers nearly 50% of Kam Nui Archipelago. Forest regeneration is very slow here due to the extreme climate, especially water stress in the dry season.

Wildlife
The park bird list currently stands at 138 species, with 80 Resident, 54 winter visitors and 4 passage migrants. The optimum time to visit the park for bird watching is between December to February, with many migrating birds present and the optimum weather conditions.

Important bird species recorded in the park include; White-bellied sea-eagle (Haliaeetus leucogaster), Changeable hawkeagle (Spizaetus cirrhatus), Common Sandpiper (Actitis hypoleucos), Great knot (Calidris tenuirostris), Orange-breasted pigeon (Treron bicincta), Brown-winged kingfisher (Halcyon amauroptera), Blue-and-white flycatcher (Cyanoptila cyanomelana), Copper-throated sunbird (Nectarinia calcostetha), Paddyfield warbler (Acrocephalus agricola) and Mangrove whistler (Pachycephala grisola).

Mammals recorded in the park include; Common treeshrew (Tupia glis), Malayan flying lemur (Cynocephalus variegatus), Slow loris (Nycticebus coucang), Pig-tailed macaque (Macaca nemestrina), Stump-tailed macaque (M. arcttoides), Crab eating macaque (M. fascicularis), Banded langur (Presbytis femoralis), Masked palm civet (Paguma larvata) ,Binturong (Arctictis binturong) Mouse deer (Tragulus spp.) Pangolin (Manis javanica), Black giant squirrel (Ratufa bicolor) and Common wild pig (Sus scrofa). These species were recorded in a survey in 1988 and the continued presence of some of these animals is now in doubt.