Siphandone is an island which surrounded by the mighty Mekong as it flows through southern Laos. A spectacular waterfall punctuates the unique geography of this region. Like the rest of Laos, this area is quiet, quaint, and a great place to relax.
It is easily reached from Cambodia. Travelers heading overland from Cambodia can catch a ferry or speedboat to the islands.
(http://hubpages.com/hub/The_4000_Islands_of_Laos)