The province is at the west end of the Khorat Plateau, separated from the Chao Phraya river valley by the Phetchabun and Dong Phaya Yen mountain ranges. Two national parks are in the province: Khao Yai in the west and Thap Lan in the south. Both parks are in the forested mountains of the Sankamphaeng Range, the southern prolongation of the Dong Phaya Yen mountains
Nakhon Ratchasima, or "Khorat," is a large province on the northeastern plateau and acts as a gateway to other provinces in the northeast. It is 259 kilometres (161 mi) from Bangkok and has an area of around 20,494 square kilometres (7,913 sq mi), making it the largest Thai province. The province is rich in Khmer culture and has a long history.