About the Cheow Lan Reservoir (also called Chiew Larn)

In mid-1980s, the Rajaprabha dam was built to increase Thailand's electrical power needs by the Electrical Generating Authority of Thailand, the dam that eventually inundated a total of 160km2 of the Khlong (river) Saeng valley to become the Cheow Lan reservoir in 1986. The water body extends for more than 50km with over 160 small islands and many fjords and bays.

Khlong Saeng Wildlife Sanctuary was once a magnificent natural watershed. It still harbours some very impressive animals such as elephant, otters, gaur, tapir, serow, sambar, wild boar, clouded leopard and sun bear. There are six hornbill and two gibbon species in the area. The stump-tailed macaque is the largest primate, and dusky langur or leaf-monkeys are common. White-bellied sea eagle, lesser fish-eagle, the rare Grey-headed Fish Eagle and osprey are common birds of prey in the park.

Where rivers and forest previously existed, the Cheow Lan dam now provides easy boat access to this virgin wilderness. Huge forest trees stand as a reminder of what disappeared beneath the flood more than a quarter of a century ago. Some trees still stand but many have come crashing down especially upstream where decaying is severe. These trees have created shelter for the dams fish population and most of them are covered with wild orchids

Probably the most impressive scenic site in the sanctuary is the massive limestone karsts formations in the southern part of the dam that were formed over 200 million years ago. These massive outcrops, some reaching as high as 960m, look almost ''architectural'' in design and are as impressive as the famous karsts in Phang Nga Bay and the ones in Gujin in China. These Karsts are the remnants of a prehistoric coral reef that once were here.

The rivers and streams in the northern part of the dam are the spawning areas for many of the lakes fish species. Giant Snakehead fish and some of the lakes catfish species spawns in the lower parts of the rivers, the Hampala Barb and the Thai and the Blue Mahseer in the head waters. The spawning season is during the rainy season from May to November.