Neak Pean ('The entwined serpents') is an artificial island with a Buddhist temple on a circular island in Preah Khan Baray built during the reign of King Jayavarman VII. A baray is an artificial body of water. The central pool represents the Himalayan Lake Anavatapta, located at the summit of the universe, which was believed to give birth to the four great rivers of the world. These four rivers are represented at Neak Pean by four gargoyle-like heads which, when opened, would permit water to flow from the main pool to the four smaller pools.