Isan is Thailand's largest region, located on theKhorat Plateau, bordered by the Mekong River (along the border with Laos) to the north and east, by Cambodia to the southeast and theSankamphaeng Range south of Nakhon Ratchasima. To the west it is separated from northern and central Thailand by the Phetchabun Mountains.
The north and the east of the region border Laos divided by Mekong River from Loei to Ubon Ratchathani. The south of the region borders Cambodia.