Koh Rong Sanleum

Koh Rong Samleum (Khmer: កោះរ៉ង់សន្លឹម, also Kaoh Rong Samloem) is an island off the coast of Sihanoukville, Cambodia. It includes a large heart-shaped bay with shellfish cultivation and beaches on the north coast towards Koh Rong.
Also Koh Rong Samlon is home to the privately owned business Marine Conservation Cambodia, which works with the local villagers in order to protect the unique marine life around the island.

It can be reached by boat from Sihanoukville in about 2 hours. It harbors a small fishing village, three major beaches and several minor beaches almost entirely uninhabited, including some very nice, sheltered beaches on the north side near Koh Kon.

Currently only a few tour operators on the beach in Sihanoukville offer snorkeling trips to the island. EcoSea Dive and Island Divers offers diving excursions and overnight trips to their respective bungalows on the northern part of the island. Other tourist resorts and bungalow-settlements on the island include "M'Pay Bay" bungalows and "Lazy Beach," the latter which is located on the western side of the island.

sourced:cambodia-tourism.org