Kampong Thom to Koh Kong Drive: Complete Road Trip Guide

The drive from Kampong Thom to Koh Kong is a journey across Cambodia's central plains to the southwestern coast, a distance of about 310 kilometers. This route takes you through the country's heartland, past ancient temples and booming capital, into the Cardamom Mountains' rainforest.

Historically, the road from Kampong Thom to Phnom Penh follows the same corridor as the ancient Angkorian highway, and you'll cross the Sen River near Sambor Prei Kuk, a pre-Angkorian capital from the 7th century. The final stretch into Koh Kong traverses the Cardamom Mountains, a region once notorious for Khmer Rouge strongholds, now a biodiversity hotspot.

Below is a summary of key logistics for the journey:

Driving the entire route non-stop typically takes 7–9 hours, including breaks. The route is a mix of smooth national highways and steep mountain passes.

As you leave Kampong Thom, the flat rice paddies stretch to the horizon, punctuated by sugar palm trees. Sambor Prei Kuk, a UNESCO World Heritage Site, is a must-stop for its brick temples enveloped by dry forests. In contrast, the Cardamom Mountains offer misty peaks and rainforest waterfalls, such as the Tatai Leu Waterfall near Koh Kong.

The route's beauty shifts with the climate; during the dry season (November to April), it's dusty and hot, while the wet season (May to October) brings lush greenery and occasional landslides, especially in the mountains. Plan for scenic but potentially slippery roads in the wet months.

In terms of commerce, you'll pass through bustling markets in Kampong Thom, Skuon (famous for fried spiders), and Kraol Kou. These roadside stalls are perfect for buying local fruits, like mangoes and palm sugar. For a meal, stop at local diners (certainly not Western chains) offering fish amok or beef lok lak; in Sre Ambel, try the river fish.

Road quality on NR6 and NR4 is generally good with clear signage, but the NR48 segment in the Cardamoms is winding and narrow, demanding careful driving. In the mountains, watch for fallen rocks and logging trucks. The speed limit is 40 km/h in curves; obey it to avoid rollovers. Driving after dark is discouraged without experience, as some stretches have no streetlights and animals may cross.

For families, the journey offers educational stops like Sambor Prei Kuk, but there are no dedicated children's playgrounds. Most attractions are nature-oriented; keep kids excited with waterfall visits and monkey spotting. As for pets, many restaurants and stops welcome them, but check in advance. Keep pets leashed at all times, especially near wildlife.

Fatigue is a real concern on a 9-hour drive. Plan to stop every 2 hours. Recommended rest zones: Skuon (after 70 km), Phnom Penh (after 168 km), and Sre Ambel (after 310 km). Coffee shops and guesthouses abound in these towns. Also, a useful resource for planning stops is how to find the best stops and hidden gems between cities.

Hidden off-route spots include the Kampong Phluk fishing village near Phnom Penh (detour 30 km), and the Peam Krasop Wildlife Sanctuary mangroves near Koh Kong (detour 15 km). Both offer serene escapes from the road.

National Road 6 connects Kampong Thom to Phnom Penh, while National Road 4 and then National Road 48 take you to Koh Kong. The highways are in good condition, especially NR4, a major logistics corridor with heavy truck traffic. Expect tolls? No, but fuel stations are frequent along NR4; in the Cardamoms, they become sparse.

Fuel costs: as of 2025, regular gasoline in Cambodia ranges from $3.70 to $4.10 per gallon. The total fuel expense for a typical sedan averages $35–$45. If you drive a large SUV or 4x4, budget $50–$60. Carrying extra fuel is not necessary as long as you fill up at Sre Ambel, the gateway to Koh Kong.

Key logistics at a glance:

• Highways: NR6, NR4, NR48.
• Total distance: ~310 km.
• Driving time: 7–9 hours with stops.
• Road tolls: none on this route.
• Speed limits: 60-80 km/h in urban, 90 km/h on highways.