Vat Phou or Wat Phu (temple-mountain) is a ruined Khmer temple complex in southern Laos.
It is located at the base of mount Phu Kao, some 6 km from the Mekong river in Champasak province. There was a temple on 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 linga was bathed in water from a mountain spring. The site later became a centre of Theravada Buddhist worship, which it remains today.

Reference :
É. Aymonier, Le Cambodge. II Les provinces siamoises, Paris 1901;
E. Lunet de Lajonquiére, Inventaire descriptif des monuments d’Indochine. Le Cambodge, II, Paris 1907;
H. Marchal, Le Temple de Vat Phou, province de Champassak, Éd. du département des Cultes du Gouvernement royal du Laos
H Parmentier, «Le temple de Vat Phu», Bulletin de l’École Française d’Extrême-Orient, 14/2, 1914, p. 1-31;
M. Freeman, A Guide to Khmer Temples in Thailand and Laos. Weatherhill 1996. ISBN 0-8348-0450-6.
M. Santoni et al., «Excavations at Champasak and Wat Phu (Southern Laos) », in R. Ciarla, F. Rispoli (ed.), South-East Asian Archaeology 1992, Roma 1997, p. 233-63;