Cambodia’s landscape is characterized by a low-lying central plain that is surrounded by uplands and low mountains and includes the Tonle Sap (Great Lake) and the upper reaches of the Mekong River delta.
To the north the Cambodian plain abuts a sandstone escarpment, which forms a southward-facing cliff stretching more than 200 miles (320 km) from west to east and rising abruptly above the plain to heights of 600 to 1,800 feet (180 to 550 meters).
Flowing south through the country’s eastern regions is the Mekong River. East of the Mekong the transitional plains gradually merge with the eastern highlands, a region of forested mountains and high plateaus that extend into Laos and Vietnam.
Cambodia’s climate, like that of the rest of Southeast Asia, is dominated by monsoons, which are known as tropical wet and dry because of the distinctly marked seasonal differences.
Cambodia has a wide variety of plants and animals. There are 212 mammal species, 536 bird species, 240 reptil species, 850 freshwater fish species (Tonle Sap Lake area), and 435 marine fish species. Much of this biodiversity is contained around the Tonle Sap Lake and the surrounding biosphere.