The Cardamom Mountains hold the largest unbroken rainforest left in mainland Southeast Asia, a range running three hundred kilometres across south-western Cambodia, and it came through the twentieth century intact for an ugly reason. Khmer Rouge fighters held out in these hills until 1998, and nobody walked willingly into their minefields. When the last of them surrendered the range opened, and loggers, poachers and land grabbers arrived almost at once. Conservation groups moved in behind them from 2002, and two national parks followed in 2016. A large slice of the southern range is now a carbon-credit project: companies pay for the trees to be left standing, and that money helps fund the rangers. The scheme was suspended in 2023 over allegations that Chong families had been pushed off their farmland.
Most trips start at Chi Phat, where the long treks take you into the interior: hours of hill forest, river crossings, nights slung in a hammock under a tarp. The man walking ahead of you grew up hunting or logging these ridges and now works them for the community scheme, reading tracks and calls you would pass straight by. Over the crest the rain stops. The seaward flank takes 3,800 to 5,000 millimetres a year while the eastern slopes get roughly a quarter of that, so rainforest and drier deciduous woodland sit barely seventy kilometres apart. Where the rivers reach the sea at Peam Krasop, longtails thread channels walled with stilt roots past hamlets built on poles. On the Tatai the lodges stand on decks over the water, close enough to watch a rainstorm come over the hills, cross the river as a grey wall and move on within the hour. In the dry months the falls upstream drop to a few chutes and the rock shelf below fills with pools that shock you even in April. Gibbons open up in the first hour of light. And in these rivers, in 2000, a survey found the Siamese crocodile alive after the world had written it off — in 2024 five nests here produced sixty hatchlings.