Located in Champassak Province in southern Laos, Pakse is the second largest town of Laos. The primary attraction in Pakse is the Khmer archeological ruin of Wat Phou a Khmer temple dating from the 8-11th centuries and classified as a World Heritage Site. It was built by the founder of the first Khmer empire, Jayavarman II. Other attractions in the Champasak region include the 4,000 islands of Si Phan Don near the Cambodian border; elephant trekking in Ban Khiet Ngong and Southeast Asia’s highest waterfall, Khong Phapeng.