Most visitors to Cambodia follow the well-trodden triangle of Siem Reap, Phnom Penh and Sihanoukville. Few realise that there’s a hidden route connecting Siem Reap to Koh Kong that bypasses the capital entirely. This journey cuts through some of the country’s wildest landscapes, from colonial-era towns to rainforest-covered mountains, ending at the sleepy coast near the Thai border. It is long, rugged, and often overlooked—but that’s exactly the appeal.
This is not a trip for time-pressed tourists. This is for the curious, the patient, and the ones looking to actually see something beyond Angkor Wat and cocktail buckets. Here’s how to do it, what to expect, and why it might just be one of the most rewarding overland routes in Cambodia.
Table of Contents
Siem Reap to Battambang
The first leg takes you southwest toward Battambang, a journey of around 170 kilometres. Buses and minivans run daily, taking 3 to 4 hours depending on stops. Tickets are usually around $10. If you’re self-driving, expect around 3 hours on mostly paved roads.
Battambang is not just a transit point. It is Cambodia’s second-largest city but still manages to feel like a small town. There’s enough here to warrant an overnight stay. You can visit colonial-era architecture, eat some decent street food, or ride the Bamboo Train if you want to experience a tourism gimmick that is somehow still fun. It also makes a good place to recharge before the more adventurous section of the trip.
Battambang to Pursat and Onward to Osoam
From Battambang, the road continues south through the countryside toward Pursat. This stretch is about 110 kilometres and takes 2.5 hours by car. Shared taxis run between the two towns, and local buses also serve the route.
Pursat is a riverside town with a low-key charm. Not much happens here, but it’s a good place for a meal and to stock up on essentials. From here, the trip veers off the tourist radar completely.
Roughly 70 kilometres from Pursat is the small village of Osoam. Getting there involves a climb into the Cardamom Mountains. The road is unpaved in sections and can get muddy during the rainy season. Driving this part takes about 2.5 hours if conditions are good. There are occasional shared trucks and pickups that run this route, but they are infrequent and best suited to those with patience and no luggage.
Osoam itself is a tiny, jungle-fringed community that’s slowly becoming a hub for eco-tourism. A few guesthouses and bungalows cater to travellers passing through or looking to explore the surrounding forest. You can swim in waterfalls, trek into the jungle, or just sit with a cold drink and enjoy the quiet. No Wi-Fi, no crowds, just frogs and diesel fumes from the odd passing truck.
Crossing the Cardamom Mountains
Beyond Osoam, the road gets narrower and more scenic as it cuts through the heart of the Cardamoms. The mountain range here is thick with jungle and low in infrastructure, which is part of the appeal. This is one of the last great wilderness areas in mainland Southeast Asia. If you’re lucky, you’ll spot monkeys on the roadside and hornbills flying overhead.
The drive through the Cardamoms takes about 3 hours depending on your speed and the weather. Some parts are newly paved, while others still involve gravel and potholes. There are no real towns, but you’ll pass through small villages and checkpoints where locals might offer fuel, snacks or directions that may or may not be accurate.
Driving this stretch is not for the nervous, but it’s manageable with a decent vehicle and some patience. It’s also the most beautiful part of the entire journey, with panoramic views, hanging mist, and the occasional rogue cow.
Arriving in Koh Kong
Eventually the road descends toward Koh Kong town, located on the coast near the Thai border. The transition is stark. After days of forest and dust, you emerge into a laid-back town with broad streets, a riverside promenade, and some surprisingly good seafood.
Koh Kong is not a tourist hotspot and probably never will be. There’s a small expat presence, some decent accommodation, and a couple of chilled bars. It is quiet, slow and refreshingly normal. The nearby mangrove forests are worth exploring, and there are boat trips available to Koh Kong Island, which has long, empty beaches and almost no development. There’s also a small street food scene for those willing to hunt it down.
This is not a place full of attractions. But if you’ve made it all the way from Siem Reap to Koh Kong, you probably weren’t looking for all-you-can-eat buffets and banana pancakes anyway.
Getting Out and Getting Onward
Once you reach Koh Kong, you’ve got a few choices depending on how much adventure you have left in you. Here’s how to continue:
Koh Kong to Phnom Penh
Travel time: 5 to 6 hours by bus
Options: Daily minivans and local buses leave in the morning. Shared taxis are faster but cost more.
Distance: Around 290 kilometres
Fare: $10 to $15
Koh Kong to Sihanoukville
Travel time: 4 to 5 hours
Options: Buses and minivans run this route with one or two daily departures. Driving yourself is also easy as the road is paved and in good condition.
Distance: 230 kilometres
Fare: $12 to $15
Bonus: Sihanoukville connects to Cambodia’s only functioning train network, offering a rare rail journey to Phnom Penh.
Koh Kong to Pursat
Travel time: Around 4 hours
Options: Shared taxis and the occasional minivan. Limited public transport. Best suited for those with their own vehicle.
Distance: Around 200 kilometres
Fare: $10 to $12
Koh Kong to Siem Reap
Travel time: 8 to 10 hours
Options: There are now direct buses between Koh Kong and Siem Reap, though departures are infrequent. The long route takes you back through Pursat and Battambang.
Distance: Around 470 kilometres
Fare: $18 to $25 depending on company and route
Final Thoughts
The route from Siem Reap to Koh Kong is not the most efficient. It’s not fast, it’s not comfortable, and it won’t win any awards for convenience. But for those who value the journey as much as the destination, this trip delivers. You’ll pass through provinces most travellers skip entirely, eat in roadside stalls with no names, and drive through some of the last true wilderness in the country.
It’s not a journey for everyone. But if you’re the type who prefers jungle treks to air-conditioned cafes, or dusty roads to polished tour buses, then the overland route from Siem Reap to Koh Kong might just be one of Cambodia’s best-kept secrets.
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