1. Southwestern Beach, Koh Rong
Koh Rong is easily one of the Gulf of Thailand’s most gorgeous islands, with 43 kilometers of beach. On the southwestern side of Koh Rong the beach stretches for nearly five kilometers -- 5,000 meters of untouched white sand fringed with palm trees and dazzling turquoise waters. At the southernmost end of this beach are rocks where snorkelers can watch schools of colorful rabbitfish, sergeant fish and parrot fish.
2. Long Set Beach, Koh Rong
The southernmost cove of Koh Rong hosts a beach that the locals call Long Set, after the farmer who lives there growing coconuts, mangoes and cashews. With nearly empty white sand beaches and placid aquamarine waters, Long Set Beach is just a short walk away from the accommodations on the main part of southeast Koh Rong and is an ideal place for sunning, collecting shells and crabbing.
On nights where the moon is waning, night swimming can reveal bio-luminescent plankton that cause a ethereal phosphorescence in the water.
3. Lazy Beach, Koh Rong Saloem
All of the beaches on Koh Rong Saloem, an island two hours off the coast of Sihanoukville, will have you gaping in awe, but Lazy Beach is particularly beautiful. Shaded by pine trees and benefiting from a daily sweep to keep it spotless, the golden sands of Lazy Beach make for excellent daytime sunning.
The waters around the beach have many snorkeling options and other parts of Koh Rong Saloem are a favorite of divers and fishing enthusiasts from the mainland. Evenings, you can watch the deep pink sunsets from the beach with a tropical cocktail in hand.
4. Koh Thmei beach, Ream National Park
Ream National Park is home to some of Cambodia's most exquisite beaches, including those on Koh Thmei, a small island flanked by mangrove forests. Koh Thmei is uninhabited, except for one set of bungalows and dozens of different species of birds. The beach next to the boat dock is a sea of thousands of glittering shells. The beach to the east of the dock is lovely pine-shaded yellow sand and if you get there early enough, you can catch a gorgeous sunrise.
5. Sokha Beach, Sihanoukville
Privately owned Sokha Beach is the best of Sihanoukville's beaches, with wide white sands stretching for over a kilometer and shallow, placid waters perfect for swimming. A small portion of the beach is still open to the public, but the rest is only available to hotel guests or those who pay for a day pass, which also includes access to the resort's pool.
Although the privatization of Sokha Beach is a loss for the locals, tourists can enjoy the immaculate sand and hawker-free relaxation at this relatively quiet and sedate beach.