Koh Rong

The Water Was Glowing

I will never forget the first time I saw the bioluminescent plankton. It was my second night on Koh Rong, a moonless evening with more stars than I had seen since childhood. My guesthouse host had mentioned the plankton might be active, so I walked to the darkest stretch of Long Set Beach, away from the scattered light of bungalow restaurants, kicked off my shoes, and waded into the warm water.

Nothing happened at first. Then I swept my arm through the surface, and the water exploded in electric blue light. Every movement left trails of luminescence — my fingers, my feet, the ripples I created. I stood in the shallows for an hour, running my hands through liquid starlight, laughing out loud at something I had read about but never believed could look this extraordinary in reality. Other travelers appeared on the beach, saw the glow, and waded in with the same disbelieving wonder. By midnight, there were a dozen of us, strangers united in the shared absurdity of swimming in light.

That moment encapsulates what Koh Rong does best. This is an island that delivers experiences you cannot manufacture, cannot expedite, and cannot replicate anywhere else in Cambodia. The beaches are among the most beautiful in Southeast Asia — Long Set Beach alone stretches for 7 kilometers of white sand so fine it squeaks underfoot, fronting water that shifts between transparent turquoise and deep sapphire depending on the depth and the hour. The jungle interior is dense and untrailed in places, hiding waterfalls and villages accessible only on foot. The diving, while not world-class, reveals seahorses and nudibranchs to anyone willing to drop below the surface. And the entire package exists at a fraction of the cost of comparable Thai or Indonesian islands.

I have spent a cumulative three weeks on Koh Rong across multiple visits, and each trip reinforces the same conclusion: this is Cambodia’s finest island, operating at a level of natural beauty that most Southeast Asian beach destinations lost to development years ago. The island is changing — the pier village grows louder, the construction of a new airport on the island threatens to accelerate development dramatically — but for now, Koh Rong remains the real thing. If you are reading this in 2026, go soon.

My approach on every visit has been the same: take the first ferry from Sihanoukville, hire a boat from the pier to Long Set Beach (the opposite side of the island from the party village), check into a bungalow, and not leave that beach for three days. It sounds boring on paper. In practice, it was the most restorative travel experience I have had in a decade.

What Makes Koh Rong Different

Koh Rong occupies a rare position in Southeast Asian island tourism: it is beautiful enough to compete with Thailand’s best islands but undeveloped enough to feel genuinely remote. The absence of ATMs, the patchy WiFi, the lack of paved roads, and the boat-only access create a natural filter that keeps the island from becoming another Koh Phi Phi or Boracay. The travelers who make it here tend to be looking for something specific — silence, nature, disconnection — and the island delivers all three.

The geography helps. Koh Rong is Cambodia’s second-largest island at 78 square kilometers, and most of that area is uninhabited jungle. The population centers are tiny: Koh Tuch village near the ferry pier (backpacker bars, dive shops, and budget accommodation), Long Set Beach on the west coast (quiet bungalow operations), and a handful of isolated resorts scattered along smaller beaches. Walking from one side of the island to the other takes 3-4 hours through dense jungle on an unmarked trail. The scale of the place means that even during peak season, you can find beaches where you are the only person.

The bioluminescent plankton are Koh Rong’s most famous feature, but the full range of natural assets is broader than most visitors realize. The coral reefs around the island and its smaller neighbors support a marine ecosystem that includes over 200 species of fish. The jungle interior harbors hornbills, monitor lizards, and a population of slow lorises. The sunsets over the open ocean from the west coast beaches rank among the most dramatic I have seen — the absence of islands or landmass on the western horizon means the sun drops into water with an unbroken descent.

The island is also divided between two dramatically different travel experiences. Koh Tuch village caters to the backpacker party circuit — fire shows, cheap cocktails, loud music until late. Long Set Beach and the isolated resorts cater to travelers seeking the opposite. Both experiences exist on the same island without much overlap, which means Koh Rong serves a remarkably wide spectrum of traveler types. I have never been to the party side for more than a transit stop, but I have heard compelling reports from travelers who loved it.

What to Do on Koh Rong

Long Set Beach — All Day, Every Day ($0)

Seven kilometers of white sand, turquoise water, and very few people. Long Set Beach (also called Long Beach or 4K Beach) is the main attraction on Koh Rong and arguably the most beautiful beach in Cambodia. The sand is powder-fine and the water is warm enough to stay in for hours. The beach faces west, delivering exceptional sunsets. Swimming is generally safe in the designated areas, though currents can be strong at the southern end — ask locally. I spent three days here doing nothing more ambitious than swimming, reading, and eating, and it was enough.

Bioluminescent Plankton Night Experience ($0-15)

The plankton are most visible on dark, moonless nights between June and November, though they appear year-round with varying intensity. Walk to a section of beach with minimal light pollution (Long Set Beach works, as do some smaller coves), wade into the water, and disturb the surface. The blue glow is caused by dinoflagellates — single-celled organisms that produce light when agitated. Guided tours ($10-15) take you by boat to coves where the concentration is strongest. On my best night, every wave breaking on the shore left a trail of blue fire across the sand.

Jungle Trek Across the Island ($0, or $10-15 guided)

The cross-island trail from Koh Tuch to Long Set Beach takes approximately 2-3 hours through dense tropical jungle. The path is marked but not maintained — expect mud, roots, steep sections, and humidity that will soak your shirt in minutes. The payoff is immersion in a jungle ecosystem that feels untouched: massive buttress-rooted trees, birdsong from the canopy, and the possibility of seeing monitor lizards, macaques, or hornbills. Bring water (at least 2 liters), wear sturdy shoes, and do not attempt this alone in wet season when the trail becomes treacherous. A guide ($10-15, arranged through your guesthouse) adds safety and wildlife spotting expertise.

Diving and Snorkeling ($15-70)

Two PADI-certified dive shops on the island offer Discover Scuba ($60-70), fun dives ($30-40), and Open Water certification ($300-350). The dive sites around Koh Rong and the neighboring islands feature soft corals, seahorses, nudibranchs, cuttlefish, and occasional ray sightings. Visibility is best from November through April (5-15 meters). Snorkeling trips ($15-25) visit the healthiest reef areas off the island’s southern tip and around Koh Rong Sanloem. I did a two-dive day trip ($65) and was rewarded with a thorny seahorse and a school of barracuda — not the Maldives, but genuinely enjoyable.

Kayaking to Hidden Beaches ($5-10 per hour)

Rent a kayak from your guesthouse or beach bar and paddle along the coastline to discover small coves and beaches inaccessible by foot. The west coast of Koh Rong has a series of miniature beaches tucked between rocky headlands, most of which you will have entirely to yourself. A two-hour paddle from Long Set Beach heading north took me to a cove with water so clear I could see my shadow on the sandy bottom 4 meters below. Bring water, sunscreen, and a dry bag for your phone.

Koh Rong Sanloem Day Trip ($15-25 return boat)

Koh Rong’s smaller, quieter neighbor is a 30-minute boat ride away and makes for an excellent day trip (or multi-day stay). Saracen Bay is the main beach — a horseshoe of white sand with calmer water than most Koh Rong beaches, lined with bungalows and restaurants. The snorkeling off the southern tip of the island is considered the best in the area. Long boats run between the islands throughout the day ($10-15 one way). I split my most recent visit between three nights on Koh Rong and two on Sanloem.

Sunset from the West Coast ($0)

Long Set Beach faces almost perfectly west, and the sunsets are consistently spectacular. Without any landmass between you and the horizon, the sun drops directly into the ocean in a display that evolves from gold to orange to crimson to purple over about thirty minutes. The best viewing position is from the beach itself, drink in hand, feet in sand. No entrance fee, no reservation required — just show up and look west.

Where to Eat on Koh Rong

Tree House Bungalows Restaurant ($4-10 per person)

Located at Long Set Beach, this elevated restaurant serves Khmer and Western food with views through the tree canopy to the ocean. The fish curry, the pad thai, and the grilled squid are all reliable. The fruit shakes are made with fresh island fruit and cost $2. The vibe is barefoot and unhurried, which is exactly right for an island restaurant.

Monkey Island Bar & Restaurant ($3-8 per person)

A beachfront bar and restaurant at Long Set Beach that doubles as the social hub for the quiet side of the island. The BBQ fish plate ($6), the green curry ($4), and the enormous banana pancakes ($2.50) are regular orders. Happy hour beers are $1.50. The firepit evenings on the beach create a communal atmosphere where solo travelers merge into groups effortlessly.

Koh Tuch Pier Restaurants ($2-6 per person)

The cluster of restaurants around the ferry pier in Koh Tuch village serves the cheapest food on the island. Fried rice ($2), noodle soup ($2.50), grilled fish ($3-5), and fruit shakes ($1.50) are the standards. The quality varies between stalls — look for the ones with the most local customers. The night market that sets up near the pier on busy evenings has BBQ skewers ($0.50-1) and fresh coconuts ($1).

The One Resort Restaurant ($5-12 per person)

The restaurant at The One Resort on Long Set Beach serves the most polished food on the island. The seafood platter (grilled fish, prawns, and squid with kampot pepper dipping sauce, $12) is worth the splurge. The Khmer curry and the stir-fried morning glory are consistently good. Breakfast here — eggs, toast, fruit, and Cambodian coffee — is a strong start to a beach day.

Beach BBQ (arrange through guesthouse, $8-15 per person)

Several guesthouses on Long Set Beach organize evening BBQs where fresh fish, prawns, and squid are grilled over coals on the sand. The meal typically includes rice, salad, and unlimited beer. The cost ($10-15 per person) is fixed and covers everything. Eating grilled seafood on a dark beach with the Milky Way overhead and the occasional glow of bioluminescent waves is a peak Koh Rong experience.

Where to Stay on Koh Rong

Budget: Nest Beach Club ($6-10 dorm, $15-25 bungalow)

A backpacker-oriented operation near Koh Tuch with dorms and basic bungalows. The bar hosts regular events, the beach access is direct, and the social atmosphere makes meeting people effortless. The dorms have fans and mosquito nets — functional but not luxurious. The bungalows are a better value, with private bathrooms and enough space to spread out. Location is close to the pier village, which means easy access to food and nightlife but also noise.

Mid-Range: The One Resort ($40-80/night)

My accommodation of choice on Koh Rong. Beachfront bungalows on Long Set Beach with air conditioning, hot water, private balconies, and a restaurant. The rooms are simple but clean and comfortable, and the location — directly on the beach with the ocean as your view — is the real luxury. The generator provides power until midnight (bring a power bank). The staff can arrange snorkeling trips, boat transfers, and kayak rentals.

Luxury: Song Saa Private Island ($800-2,000/night)

Cambodia’s most exclusive resort occupies two private islands connected by a bridge near Koh Rong. Overwater villas, a marine conservation program, a spa with ocean views, and a restaurant using ingredients from their own garden and local fishing communities. This is one of those properties where the price includes not just a room but a complete experience — private snorkeling excursions, sunset cruises, cooking classes, and a silence that money can purchase but not replicate. Not in my budget, but worth mentioning as the pinnacle of Cambodian island luxury.