Two hours south of the bustle of Sihanoukville, a slow boat gets you to Lazy Beach on Koh Rong Samloem, Cambodia. There's not much to do here but eat fresh seafood, drink cold
Angkor beer and relax. There's some decent snorkeling on the edges of the bay and a few walks across the island. Basic bungalows on the beach are comfortable and well-equipped and there's generator power for 4 hours a night. No phones, no TV, no WiFi.