Don Khong is the biggest island in Laos and the main island of the Khong District and Si Phan Don (4000 Islands) area. It is connected with the mainland by a 700 meters long bridge spanning the Mekong river. A quiet and serene island with a few nice things to see and do as well. A small museum offers some background information about the island and the area (aks for Mister Koaum for if you are there, he speaks a little bit of English and is happy to help you). You can travel from Don Khong by boat to Don Som, Don Det and Don Khone or to one of the mainland villages.
There are minivans and buses going from Pakse to Don Khong and the other way around. Don’t expect a lot of transport options on Don Khong. The island is mostly very quiet and tuktuks and other ways of getting around are normally hard to find or not there at all. Cycling or renting a motorbike are the best options to enjoy the island. The island is 18 kilometers (11 miles) long from north to south, and 8 kilometers (5.0 miles) at its widest point.
Tham Phu Kiaw is a very small cave located a few kilometers north of Muang Khong (the town where most visitors stay on Don Khong). The cave contains some old Buddha statues and pots. It’s a relatively easy walk from the main road of Don Khong to the cave in the forests. Muang Saen on the western part of the island has a big market which is visited by people from Don Khong and surrounding islands and Cambodian people from just accross the Mekong river.