Koh Rong to Sa Kaeo Road Trip: Highlights & Logistics

Koh Rong's Gulf of Thailand waters hide an old Khmer Rouge naval base, but the island's real draw is its bioluminescent plankton. To reach Sa Kaeo near the Cambodian-Thai border, you'll cross the Cardamom Mountains and then flat farmlands, a microcosm of Cambodia's terrain.

The journey involves a ferry from Koh Rong to Sihanoukville (45 minutes), then a drive north on National Road 4 (NH4) to Phnom Penh, continuing on National Road 5 (NH5) to Bavet, then crossing into Thailand and taking Route 33 to Sa Kaeo. Total driving time is 9–11 hours depending on border crossing and traffic.

The NH4 from Sihanoukville to Phnom Penh is a well-paved two-lane highway, but heavy truck traffic and occasional potholes near construction sites demand alertness. After Phnom Penh, NH5 to Bavet is similarly maintained. The Thai side, Route 33, is smooth and well-signposted.

Fuel stations appear roughly every 50–80 km along both highways, and diesel costs about $1.00–$1.10 per liter in Cambodia and 30–32 baht in Thailand. A mid-size SUV consumes roughly $60–$80 in fuel for the whole journey.

• Border crossing at Bavet/Aranyaprathet is open 7am-10pm, allowing same-day passage.
• Keep your car's registration and insurance documents handy for customs.
• Toll fees: none on Cambodian public highways; Thai Route 33 has no tolls.

Leaving the coast, the road climbs through the Cardamom Mountains, a dense rainforest stretch where you might spot wild elephants at dawn. In the dry season (November-April), the mountains are a hazy green; in the wet season, waterfalls cascade alongside the road.

Inland, the landscape flattens into rice paddies and sugar palm groves. Small roadside markets sell fresh tropical fruit and locally woven krama scarves. The town of Kampong Speu is known for its palm sugar production, a sweet stop for an authentic Cambodian treat.

For advice on how to find the best stops and hidden gems between cities, use Wayro's community tips.

On NH4, overtaking lanes are rare, and motorbikes often weave between cars. Cambodia sees a high rate of road accidents, so keep a two-second following distance and use your horn on blind corners.

For families, the Phnom Penh Sorya Mall has an indoor playground, and the Kirirom National Park offers a picnic area with waterfalls. Most roadside restaurants have basic higchairs, but bring your own baby snacks.

Pet owners should note that the border crossing is not pet-friendly without quarantine paperwork; notify both Cambodian and Thai authorities in advance. For fatigue, plan stops every 2-3 hours at designated rest areas with shaded tables and drink stalls, especially the Smart Supermarket stop before Phnom Penh.

Hidden spots: the Preah Monivong Bokor National Park entrance on NH3, a detour to a quiet pepper farm near Kampong Tralach, and the Angkor Wat temple at Khao Phra Wihan National Park on the Thai side, a lesser-known UNESCO World Heritage Site. Remember to carry bottled water and a spare tire in rural areas.