Vat Phou is a ruined Khmer Hindu temple complex in southern Laos. It is located at the base of mount Phu kao, some 6 kilometres (3.7 mi) from the Mekong in Champasak Province. There was a templeon the site as early as the 5th century, but the surviving structures date from the 11th to 13th centuries.
The temple has a unique structure, in which the elements lead to a shrine where a lingam dedicated to Lord Shiva was bathed in water from a mountain spring. The site later became a centre of Theravada Buddhist worship, which it remains today.
Vat Phou was initially associated with the city of Shrestapura, which lay on the bank of the Mekong directly east of Lingaparvata Mountain (now called Phou Khao). By the latter part of the fifth century, the city was already the capital of a kingdom that texts and inscriptions connect with both the Chenla Kingdom and Champa and the first structure on the mountain was constructed around this time.
The mountain gained spiritual importance from the lingam-shaped protuberance on its summit; the mountain itself was therefore considered the home of Shiva, and the river as representing the ocean or the Ganges. The temple was naturally dedicated to Shiva, while the water from the spring which emerges directly behind the temple was considered sacred.
Vat Phou was a part of the Khmer Empire centred on Angkor to the southwest, at least as early as the reign of Yasovarman I in the early 10th century. Shrestapura was superseded by a new city in the Angkorian period, located directly south of the temple. In the later period, the original buildings were replaced, re-using some of the stone blocks; the temple now seen was built primarily during the Koh Ker and Baphuonperiods of the 11th century.
Minor changes were made during the following two centuries, before the temple, like most in the empire, was converted to Theravada Buddhist use. This continued after the area came under control of the Lao, and a festival is held on the site each February. Little restoration work has been done, other than the restoration of boundary posts along the path. Vat Phou was designated a World Heritage Site in 2001.