The Wat Phou Hindu temple complex is located on the side of a symbolic sacred mountainside called Phu Kao, overlooking an ancient city that was previously built on the Mekong plain below. The complex dates to the 5th and 6th centuries AD, and is dedicated to the Hindu deity of Shiva.
At the top of the temple is a freshwater spring that flows from the rock, one of the reasons the temple was built and stood strong from before the main Angkorian period of Khmer rule.