Two ranges give the region its name. The Cardamoms run about 300 kilometres northwest to southeast and roughly 70 across, built from Cambrian metaconglomerate, and they hold Phnom Aural at 1,813 metres - the highest ground in Cambodia. To the south they hand off to the Elephant Mountains, known in Khmer as the Dâmrei Mountains, dâmrei meaning elephant. That range runs some 110 kilometres north to south before stopping abruptly at the coast near Kampot, topping out at Phnom Bokor, 1,081 metres. Bokor's western face catches the monsoon full on and takes some of the heaviest rainfall in the country, on the order of 150 to 200 inches a year. Those wet slopes were, until 1975, the heart of Cambodia's pepper industry. War ended that; growers only began returning in the late 1990s, and Kampot pepper has since rebuilt a reputation it had before most of the current growers were born.

Look at how you actually reach this region and the mountains define themselves by omission. Three paved highways run out of Phnom Penh: National Highway 5 northwest through Battambang to Poipet, National Highway 3 south to Kampot, and National Highway 4 southwest to Sihanoukville. Two more come in from Thailand - Highway 57 from the Ban Pakard crossing at Pailin into Battambang, and Highway 48 from the Trat crossing at Koh Kong, joining Highway 4 north of Sihanoukville. Every one of them goes around. Getting from Koh Kong directly north into the mountainous interior is possible, but it is an expedition rather than a journey, hard going even on a dirt bike, and travellers who try it are usually doing it for its own sake. This is why the interior forest survived: not policy, but topography.

There is a second reason people stay on the road. Cambodia is among the most heavily mined countries on earth, and these mountains and their northern foothills were fought over longest. The Cambodian Mine Action Centre, established in 1992, has estimated that four to six million mines and other unexploded ordnance remain in the country; some assessments put the figure higher. A national survey in 2002 found that a fifth of all Cambodian villages were contaminated. More than forty thousand people have lost limbs - one of the highest amputee rates anywhere - and roughly a third of casualties are children, most of them boys, often struck while herding or collecting scrap. The cost is not only the injury. Families cannot plant fields they know are seeded, and households headed by a survivor are close to three times as likely to be living in poverty. Clearance teams here work with detection dogs and, since 2014, with African giant pouched rats trained to scent explosive; at present funding levels the estimates for finishing run to another decade or two.

The region's shoreline now runs at two different tempos. West of Sihanoukville, Kampot and Kep keep the slower one - riverfront colonial shophouses, pepper farms climbing toward Bokor, crab sold from baskets in the shallows. Sihanoukville runs the other. What was built there in five years brought high-rise concrete, and with it organised crime: people recruited from across Southeast Asia, China and Taiwan have been held in compounds around the city and forced to run online fraud, a form of trafficking that has drawn sustained international attention. It is a strange thing to see on a map - one of Asia's last great intact forests, and directly downhill from it a boomtown built on a very modern kind of captivity. Both are the Cardamom and Elephant Mountains region. Any honest account of it has to hold both.