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.