Thailand’s largest region geographically is the Khorat Plateau in the northeast, an area defined by the mountain ranges that mark its boundaries on the west and south and by the Mekong River on the north and east. Known as Isaan, the area is bordered on the west, principally, by Thailand’s central plains, as well as by Laos to the north and east and Cambodia to the south. Once heavily forested, the land has long since been widely cleared for farming, mainly of rice, but of other crops as well, including cassava—from which tapioca derives—tobacco, and cotton. Much of the local populace are farmers, who must regularly contend with the region’s alternating periods of drought and flooding.