The reason most people come to Koh Kong is for the border crossing with Thailand at Cham Yeam. It’s a shame, however, that so few people hang around to enjoy the simple pleasures of the area – stunning virgin forests, pristine beaches, hidden waterfalls and white water rapids. At present limited access means that you’re somewhat restricted in the amount of exploration you can do, though there’s some indication that this may change, as a couple of Western-run establishments are now offering treks into the mountains and boat trips to Koh Kong island.

Koh Kong used to be a prosperous little logging town, though it’s now lapsed into a quiet backwater, with an easy familiarity. Laid out on a simple grid on the east bank of the river, the town consists mostly of wooden houses whose style owes more to neighbouring Thailand – only a few are built on stilts in Cambodian style, and there’s no colonial architecture at all.

The sights within town, such as they are, are all low-key. Locals will point you to the unexciting Red House, built for Norodom Sihanouk, who never visited it; it’s a pleasant enough walk 1km north from the centre, along the river. A pleasant jaunt can be made across the river to Resort 2000, a weekend haunt for locals, where there are thatched huts, refreshment stalls and jet skis for hire. To get there, hire a motorbike or moto (about 40 baht) and look for a dirt road branching left about 1.5km beyond the bridge, from where it’s another 2km to the beach.

A couple of small companies offer excursions to explore waterfalls upstream or the beaches on nearby Koh Kong island, which is a surprisingly large and attractive place, with pristine stretches of sand on its seaward side. The boat ride there takes about an hour.

Upriver from Koh Kong, it takes five minutes to reach a pagoda overlooking the river on the west bank, where rock paintings portray scenes of torture in hell, mixed up with what appear to be scenes of Khmer Rouge atrocities – the latter presumably painted quite recently, as this was Khmer Rouge territory until around 1997. As you journey further upstream, the imposing backdrop of the Cardamom Mountains comes into view. After about fifty minutes you’ll reach a stretch of river between towering cliffs, where you can stop to take in a pounding waterfall and a stretch of rapids.