The eastern region is often listed as a separate region destinct from central Thailand, however then excluding Nakhon Nayok. None of these regions are actually administrative subdivision, they are only geographical or statistical groupings.
CentralThailand is dominated by a large fertile plain, formed by the country’s chief river, the Chao Phraya, and its tributaries.
Thailand is bordered on the west and northwest by Myanmar (formerly Burma); on the northeast and east by Laos and Cambodia; and on the south by the Gulf of Thailand (also known as the Gulf of Siam, the northwestern portion of the South China Sea), peninsular Malaysia, and the Andaman Sea.
Thailand’s highest mountain, Doi Inthanon, rises among the northern mountains southwest of the city of Chiang Mai to a height of 2,595 m (8,514 ft).
Thailand officially is known as the Kingdom of Thailand (Prathet Thai, or "Land of the Free").
Thailand was ruled by an absolute monarchy from 1782 until 1932, when a small group of rebels seized control of the country and persuaded the king to accept the introduction of a constitutional monarchy.
Thailand is a unitary state, in which the authority of the central government is superior to that of the country's provincial and municipal governments.