Si Phan Don

If you've made it as far south as Champasak, then a visit to the Si Phan Don area—celebrated for its 4,000 Mekong River islands and freshwater dolphins—is a must. Don means island, and two of them in particular are worth visiting: Don Khong and the similarly named Don Khon, both of which are accessible by boat. Neighboring Don Det, connected to Don Khon by a bridge, attracts the backpacker crowd.