Khao Sok National Park is a jungle reserve in Southern Thailand. Its area is 739 km2 (285 sq. mi.), and it includes the 165 km2 (64 sq. mi.) Cheow Lan Lake contained by the Ratchaprapha Dam. The park is the largest area of virgin forest in Southern Thailand and is a remnant of rain forest which is older and more diverse than the Amazon rain forest. The park is traversed by a limestone mountain range from north to south with a high point of 950 m (3,117 ft). This mountain range is hit by monsoon rain coming from both the Gulf of Thailand and the Andaman Sea, which makes it among Thailand's wettest regions with an annual rain fall of 3,500 mm (137.8 in.). The park is estimated to contain over five percent of the world's species. Wild mammals include Malayan tapir, Asian elephant, tiger, sambar deer, bear, gaur, banteng, serow, wild boar, pig-tailed macaque, langur, white handed gibbons, squirrel, muntjak, mouse deer, barking deer. The world's only known amphibious centipede, Scolopendra cataracta, was discovered on a stream bank near the national park in 2001. This area is estimated to be over 160 million years old, built through tectonic movements, climate changes, erosions and sediment accumulations. Cheow Lan Lake or Ratchaprapha Dam Reservoir is an 165 km2 (64 sq. mi.) artificial lake, inaugurated in 1987 with the construction of Ratchaprapha Dam by the Electricity Generating Authority of Thailand (EGAT) as a source of electricity.
