Thailand , Thailand is the 50th-largest country by total area. It is slightly smaller than Yemen and slightly larger than Spain. 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 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.
Highest unclimbed mountain peaks from subpeaks, there is no widely agreed standard. In 1994, the International Climbing and Mountaineering Federation (UIAA) classified 82 mountain peaks in the Alps whose summits were at least above sea level and with at least of topographic prominence over any adjacent mountain pass or col, as a distinct peak. It can be difficult sometimes to determine whether or not a mountain peak has been fully summited. Long before modern mountaineering commenced in the middle of the 19th century, evidence indicates that people did indeed travel up to the summits or near to the summits of major mountain peaks.