Preah Vihear Temple is an ancient Hindu temple built during the period of the Khmer Empire in the Preah Vihear province, Cambodia. Affording a view for many kilometers across a plain, Prasat Preah Vihear has the most spectacular setting of all the temples built during the six-centuries-long Khmer Empire. As a key edifice of the empire's spiritual life, it was supported and modified by successive kings and so bears elements of several architectural styles. Preah Vihear is unusual among Khmer temples in being constructed along a long north-south axis, rather than having the conventional rectangular plan with orientation toward the east. On July 7, 2008, Preah Vihear was listed as a UNESCO World Heritage Site.
The temple was built to worship Shiva, Sikharesvara and Bhadresvara. However, the oldest parts remaining until now belongs to Koh Ker age at the beginning of 10th century when the capital city of Khmer dynasty is near Angkor.
The temple also has some features of Banteay Srei style in end of 10th century. Most of its architecture are built in the Suryayarman I and Suryayarman II in the first half of 11th and 12th century.
The architectural complex is constructed along 800m north-south axis including a road and staircases to sanctuary at the top of southern temple area. The approach to the sanctuary is punctuated by five gopuras (these are conventionally numbered from the sanctuary outwards, so gopura five is the first to be reached by visitors). Each of the gopuras before the courtyards is reached by a set of steps, and so marks a change in height which increases their impact. The gopuras also block a visitor's view of the next part of the temple until they pass through the gateway, making it impossible to see the complex as a whole from any one point.
The fifth gopura, in the Koh Ker style, retains traces of the red paint with which it was once decorated, although the tiled roof has now disappeared. The fourth gopura is later, from the Khleang/Baphuon periods, and has on its southern outer pediment, "one of the masterpieces of Preah Vihear" (Freeman, p. 162) : a depiction of the Churning of the Sea of Milk. The third is the largest, and is also flanked by two halls. The sanctuary is reached via two successive courtyards, in the outer of which are two libraries.
Preah Vihear temple is the reason of arguments between Cambodia and Thailand. On the 23rd March 1907, after the border treaty between France protectorate (1863 – 1953) and Thailand, land and temple was returned to Cambodian sovereignty. In 1954, Thai took control Preah Vihear by arm force again and removed many pieces of stones from the temple. It was the reason of Prime Minister Sihanouk during that time took the argument to the International court on 6th October 1959. The justice court awarded Preah Vihear temple on 15th June 1962 to Cambodia. Moreover the court judged that Thai Authority has to compulsorily remove their arm force and restore the temple by bring back the piece of stone which were removed under Thai occupation to Preah Vihear.