Koh Rong makes its own light. On a moonless night the sea around the island answers every movement with cold blue-green sparks, so a footstep in the shallows or a hand drawn through the water leaves a burning wake. The island is Cambodia's second largest, 78 square kilometres of jungle hills rising to 316 metres in the northwest, and it is essentially built of sand. Forty-three of its 61 kilometres of coastline are beach, more than twenty of them, shading from white through beige to pale rose. Since 2018 the water around it has been Koh Rong National Marine Park, Cambodia's first, 52,448 hectares of which only about a tenth is dry land. In 2026 the island took ninth place in the World's 50 Best Beaches, the first Cambodian entry the list has carried.
Most people land at Koh Touch, a loud strip of bars and guesthouses on the southeastern tip. Walk out of it and the rest of the island opens up. A trail crosses the interior to the fishing village of Sok San in under an hour, through forest where macaques call overhead and monitor lizards slide off the path. The long beaches on the far side run for kilometres with nothing built on them. Fishing still feeds most of the roughly 4,000 people in the island's four villages. But Koh Rong is being remade. One conglomerate has held a 99-year lease on the whole island since 2008, roads and power are pushing inland, and earthworks for a 300-million-dollar international airport began in January 2024. The plankton, awkwardly, burns brightest late in the wet season, when the sea that brings you here is at its roughest.