As the Mekong makes its way south to Cambodia it becomes peppered with islands, sandbars, and rocky outcrops. This area is known as Si Phan Don, which translates as "Four Thousand Islands." About 120km (74 miles) south of Pakse, this area is becoming increasingly popular as a getaway spot, particularly among budget travelers. The series of islands has major significance in terms of its natural beauty and the uniqueness of its wildlife, including the heavily threatened Irrawaddy dolphin. It is also where you will find the largest waterfalls in Southeast Asia, a feature that foiled plans by the French to use the Mekong as the major trade route they first intended when their empire was the major force in the area. Khon Phapheng and Somphamit waterfalls remain the major tourist attractions in the far south and given their dramatic nature one can only speculate on how disappointed the French colonizers were when they first came across them. The largest and most developed island is Don Khong, but both Don Det and Don Khon are very popular places to stay among hammock-swinging aficionados.