Nakhon Ratchasima (Thai: นครนครราชสีมา, pronounced [náʔkʰɔːn râːt.tɕʰa.sǐː.maː]) or (Khmer: នគររាជសីមា) is one of the four major cities of Isan, Thailand, known as the "Big 4 of Isan". The city is commonly known as Korat (RTGS Khorat, โคราช), a short form of its previous name. It is the capital of the Nakhon Ratchasima Province and Nakhon Ratchasima District. Nakhon Ratchasima is the heart of the Nakhon Ratchasima metropolitan area.Khorat is at the western edge of the Khorat Plateau.