[2] Upon leaving the mountains the border turns south-westwards in a broad arc, occasionally utilising rivers such as the Svay Chek, the Sisophon, the Phrom Hot and Mongkol Borei.

[2] From the 1860s France began establishing a presence in the region, initially in modern Cambodia and Vietnam, and later Laos, with the colony of French Indochina being created in 1887.

[3] These disputes faded as Cambodia became engulfed in a series of conflicts in the following decades and the disastrous rule of the Khmer Rouge, with thousands of refugees crossing the border.

[7] In an effort to stop Khmer Rouge infiltration from Thailand, Cambodia built a large fortified fence along the border in the second half of the 1980s.

[8][9] Since the advent of peace in Cambodia in the early 1990s relations with Thailand have once again soured over the Preah Vihear issue, as well as, to a lesser extent, Ko Kut island.

There are 9 checkpoints officially recognized by the Ministry of Interior which are open for cross-border local trade only, located in Ubon Ratchathani, Buriram, Sa Kaeo, Chanthaburi and Trat provinces.