Totalling 513,120 square kilometres (198,120 sq mi), Thailand is the 50th-largest country by total area. It is slightly smaller than Yemen and slightly larger than Spain.[1]
Thailand comprises several distinct geographic regions, partly corresponding to the provincial groups. The north of the country is the mountainous area of the Thai highlands, with the highest point being Doi Inthanon in the Thanon Thong Chai Range at 2,565 metres (8,415 ft) above sea level. The northeast, Isan, consists of the Khorat Plateau, bordered to the east by the Mekong River. The centre of the country is dominated by the predominantly flat Chao Phraya river valley, which runs into the Gulf of Thailand.
Southern Thailand consists of the narrow Kra Isthmus that widens into the Malay Peninsula. Politically, there are six geographical regions which differ from the others in population, basic resources, natural features, and level of social and economic development. The diversity of the regions is the most pronounced attribute of Thailand's physical setting.
The Chao Phraya and the Mekong River are the indispensable water courses of rural Thailand. Industrial scale production of crops use both rivers and their tributaries. The Gulf of Thailand covers 320,000 square kilometres (124,000 sq mi) and is fed by the Chao Phraya, Mae Klong, Bang Pakong, and Tapi Rivers. It contributes to the tourism sector owing to its clear shallow waters along the coasts in the southern region and the Kra Isthmus. The eastern shore of the Gulf of Thailand is an industrial centre of Thailand with the kingdom's premier deepwater port in Sattahip and its busiest commercial port, Laem Chabang.
The Andaman Sea is a precious natural resource as it hosts popular and luxurious resorts. Phuket, Krabi, Ranong, Phang Nga and Trang, and their islands, all lay along the coasts of the Andaman Sea and, despite the 2004 tsunami, they remain a tourist magnet.