| What it is | a riverine archipelago in the Mekong River in Champasak province, southern Laos |
|---|---|
| Main islands | Don Khong (largest), Don Som (second largest), Don Det and Don Khon |
| Rail | the first railway in Laos, the Don Det-Don Khon narrow gauge line, built by the French to bypass the Khone Phapheng Falls |
| Border | borders Cambodia |
| Gateway | Pakse is the closest large town |
Located in the southern part of the country, Si Phan Don, also known as the 4000 Islands, is a slow pace place where time seems to have no meaning. During the flood season, this area is the widest part of the Mekong River; however, when the water is low during the dry season, the islets and sandbanks appear and the number of them makes up the 4000 islands.
The Three Main Islands
Out of the thousands of islets, only three can be accessed throughout the year, these are Don Khong, Don Khone and Don Det. These islands are not only beautiful but also historical and you can find traces of French colonial villas which give the place a royal feel. Each of the islands provides different experiences, from peaceful village life, and beautiful river views, to thrills such as kayaking and cycling.
What to do in the 4000 Islands?
What are some of the things you can do in the 4000 Islands? Well. The rare Irrawaddy dolphins near the Cambodian border are a must-see! These friendly and cute creatures are quite rare to see, and this is one of the few places in the world where you can see Irrawaddy dolphins with your own eyes.
But that’s not all 4000 Islands can offer you! If you are looking for a hassle-free experience, check out customizable Laos tours from Absolute Asia Tours. Our professional consultants will ensure everything in your 4000 Islands tour such as quality accommodations, friendly tour guides, fascinating sightseeing spots,… What are you waiting for? Let’s join us to uncover this off the beaten path spot. The secret gem will not disappoint you!
The Mekong islands
English Wikipedia describes Si Phan Don, “4,000 islands”, as a riverine archipelago in the Mekong in Champasak province, part of Khong district, with some islands submerged when the river floods. The main islands are Don Khong, the largest, Don Som, the second largest, Don Det and Don Khon. The French built the Don Det-Don Khon narrow gauge line, the first railway in Laos, to bypass the impassable Khone Phapheng Falls so vessels, freight and passengers could continue along the Mekong. The islands border Cambodia, and Pakse is the nearest large town. We have not verified ferry times, dolphin sightings or the older text’s seasonal details, so check them before you go.
Sources (read in English, English Wikipedia): Si Phan Don. Last checked November 2026.
Si Phan Don: FAQ
What is Si Phan Don?
A riverine archipelago in the Mekong in southern Laos, known as the 4,000 islands.
Which are the main islands?
Don Khong, Don Som, Don Det and Don Khon.
What was the first railway in Laos?
The Don Det-Don Khon narrow gauge line, built by the French.
What is Khone Phapheng?
A series of impassable rapids that the railway bypassed.
How many days do you need?
Two to three nights.