Where it sits
Koh Kong occupies the south-west, where the Cardamom Mountains run down to the Gulf of Thailand. It holds some of mainland South-East Asia’s last large tracts of intact rainforest, and it is the rainiest province in Cambodia by a wide margin.
The provincial town is a border crossing to Thailand at Cham Yeam and is functional rather than charming. Everything worth coming for is outside it.
What to see
The Tatai river, with its waterfall and a handful of low-impact lodges accessible only by boat, is the centrepiece. The falls are swimmable in the dry season and thunderous in the wet.
Peam Krasop Mangrove Sanctuary has a long boardwalk running out through the mangrove forest to a viewing tower over the channels.
Community-based trekking and wildlife trips into the Cardamoms are increasingly well organised, and this is one of the few places in Cambodia where a serious multi-day jungle trip is straightforward to arrange.
When to come
November to March. The green season here is genuinely wet, and river levels make some trips impossible.