River systems of Thailand divides into two major branches, the " Tiền Giang" (Front River) and "Hậu Giang" (Back River). These in turn enter the South China Sea through nine estuaries. The following are the principal tributaries of Mekong River which flow through Thailand (tributaries entirely outside the Thai border not shown). The Mekong drains a considerable portion of northeast Thailand. In terms of Thai territory drained, it is second only to the Chao Phraya system. The Salawin River rises in Tibet (Tibetan: རྒྱལ་མོ་རྔུལ་ཆུ།) after which it flows through Yunnan, where it is known as the "Nujiang" River (), although either name can be
Malaysia–Thailand border and Siamese territories. This border ultimately became today's border between Malaysia and Thailand. Thailand regained control of the Kedah, Kelantan, and Terengganu during World War II when the Japanese handed them over to the kingdom, thus moving the Malay States-Siamese border southwards again. The states were returned to the British at the end of the war. There are two stretches of the Malaysia–Thailand border which is subject to dispute. The first involves the land border in the Bukit Jeli (Jeli Hill) at the headwaters of the Golok River and the second involves the continental shelf boundary in the Gulf of