Cambodia's coastline runs 440km from the Thai border to Vietnam, with the Cardamom Mountains meeting the Gulf of Thailand in a landscape of small islands, fishing villages, and mangrove estuaries. Tourism concentrated first around Sihanoukville (a deteriorating beach town that became the centre of a Chinese casino boom between 2016 and 2020, significantly changing its character) and then spread to the islands offshore and the river towns further south. Koh Rong and Koh Rong Samloem are the established island destinations; Kampot and Kep represent a quieter, more settled Cambodia that the islands don't provide.
Koh Rong: The Larger Island
Koh Rong is 78 km² and takes 2–3 hours by fast boat from Sihanoukville (USD 12–18 one way). Most visitor activity concentrates around two areas: Koh Tuch village on the south coast (where the main pier arrives, the highest density of guesthouses, bars, and restaurants) and Long Set Beach on the northwest coast (4km of white sand, accessible only on foot or by boat).
Koh Tuch has the convenience of services — accommodation, food, boat hire, the social infrastructure of a beach backpacker area — without the remoteness that some visitors seek. Long Set Beach has the remoteness without the services; a handful of beach bungalow operations exist, generator-powered, requiring advance booking. Police Beach (20 minutes by boat from Koh Tuch or 3 hours on foot) is a compromise — some accommodation, quieter than Koh Tuch, accessible without a long walk.
The interior of the island is mostly forested and accessible on marked trails. The highest point offers views over both coasts and into the Gulf of Thailand. The lack of freshwater sources has historically limited development; most accommodation uses well water or rainwater catchment. Electricity is solar or generator, typically 6pm–10pm at budget guesthouses.
Koh Rong Samloem: The Quieter Option
Koh Rong Samloem is smaller (26 km²), immediately south of Koh Rong, and receives fewer visitors despite being accessible on the same ferry routes. Saracen Bay on the east coast is the main arrival point — a curved bay with calm, clear water and good snorkelling on the reef at the bay's edges. M'Pai Bay on the north coast is smaller still, with backpacker guesthouses and a fishing village atmosphere that's closer to what the islands were like before the tourism development of the 2010s.
The slower pace of Samloem compared to Rong is partly the result of fewer ferry connections and partly a self-selection effect — travellers who take the extra step to reach Samloem generally prefer the quieter environment. There are no ATMs on the island; bring enough cash from Sihanoukville for the duration of your stay.
Bioluminescence
Both Koh Rong and Koh Rong Samloem have bioluminescent plankton (Noctiluca scintillans) in the water, visible at night when disturbed — movement through the water produces flashes of blue-green light. The phenomenon is most intense in the calmer, shallower bays (Saracen Bay on Samloem, the bays on Rong's east coast) and most visible on moonless nights. It requires complete darkness — any artificial light suppresses the visibility. Night swims off the beach or kayaking produce the most dramatic effect; organized night kayaking tours (USD 15–25) ensure you're in the right location at the right time. The brightness varies considerably by season and by year; April through October generally produces better conditions than the dry season months.
Kampot: The River Town
Kampot sits on the Praek Tuek Chhu river 5km from the Gulf of Thailand coast, 148km southwest of Phnom Penh by road (2.5 hours). The town retained its French colonial shophouse architecture more completely than Sihanoukville or Phnom Penh, and the combination of wide riverside promenade, weekly night market, and surrounding pepper plantations produces a pace that most travellers find more comfortable than the beaches.
Kampot pepper is one of the world's most renowned spice-growing regions — black and red pepper grown on the slopes of the Elephant Mountains with a flavour profile distinct from Vietnamese or Indian varieties; awarded a Geographical Indication in 2010. Plantation tours (USD 5–10, most run on the La Plantation model) cover the growing, harvesting, and processing cycle and include tasting. The green pepper, picked before drying, is available only fresh at source.
Bokor National Park, on the plateau above Kampot, holds the ruins of a French colonial hill station (casinos, church, and hotel) abandoned in 1972 and retaken by the Khmer Rouge. The ghost-town quality is part of the appeal; the new casino and hotel developments on the plateau somewhat diminish it. The 37km road from Kampot climbs through cloud forest to 1,079m; motorbike hire (USD 8–12) is the standard approach.
Kep and the Crab Market
Kep is 25km east of Kampot — a former French beach resort that declined after independence and the Khmer Rouge period and has revived slowly as a quiet coastal town. The blue swimmer crab is the reason to go: the Kep Crab Market (a row of wooden stalls on the waterfront) sells live crabs by weight, prepared with Kampot pepper and green mango in the standard Kep preparation. The combination is genuinely distinctive; a full serving for two costs USD 12–18. The market is busiest at lunch; arrive early for the best crab.
Kep National Park, a 50 km² protected forest immediately behind the town, has trails to a hilltop viewpoint over the coast and offshore Rabbit Island (Koh Tonsay), reachable by boat in 20 minutes. The beach on Rabbit Island is basic and quiet; a day trip (USD 5–8 return boat) is more practical than overnight given Kep's better accommodation options.
Getting to the Cambodian Coast
Buses from Phnom Penh to Sihanoukville run hourly, take 3.5–4 hours, and cost USD 6–10 (Giant Ibis and Mekong Express are the most reliable operators). Kampot is served by direct buses from Phnom Penh (3 hours, USD 6–8) and from Sihanoukville (1.5 hours). Kep is 30 minutes from Kampot by tuk-tuk or shared taxi (USD 8–12). Ferries to Koh Rong and Koh Rong Samloem depart from Sihanoukville port; advance booking recommended in high season (November–April).
Practical Costs
Cambodia's coast is among the cheapest beach destinations in Southeast Asia. Koh Rong bungalows run USD 15–35; mid-range beach resorts USD 50–120. Kampot guesthouses USD 15–30; nicer riverside hotels USD 50–90. Meals in Kampot and Kep: USD 3–8 at local restaurants, USD 10–18 at tourist-facing establishments. The crab market in Kep: USD 6–9 per 100g of crab. Island food and drink runs on a tourist premium (everything is brought by boat); budget USD 20–30 per day for meals on Koh Rong or Koh Rong Samloem.
