If I could only sweat around my toenails I'd hotfoot it down to the river as fast as my sturdy thighs could take me, too. And if four hours sleep a night, most of that standing up, was all I could snatch, I guarantee I'd be far tetchier about it as well. Crouched beneath a searing sun on top of the elephant's neck, knees bent and feet dangling behind her leathery ears, we lumbered down the sandy track. It had been a long, hot, dusty day and it was time for her afternoon bath.

"Hang on, enjoy the ride, but if you fall off, swim like hell," we were told. Or you might end up as the bar of slippery soap to three tons of wallowing water baby.

We'd been up at 6am to fetch the elephants from the forest, tramping through the head-high, rustling grass. Tethered with long chains throughout the woods - if they're too close together the elephants play all night and keep the hotel guests awake - their bulky frames emerged in the misty half-light through the trees.

The mahouts, small and wiry, their heads hidden in the folds of woolly Balaclavas to ward off the pre-dawn chill, untied their charges, sprang up on to the elephants' backs and, with a series of soft commands, directed them down to the water for the first dip of the day. Balancing on the broad, wrinkled backs, the mahouts washed the dust of the forest from their animals' flanks, as the elephants plunged head-first into the muddy waters, rolling from side to side.

This early morning ritual was part of the mahout-training programme at the Anantara Resort in north-east Thailand at the point where the Nam Ruak river flows into the Mekong. When the pan-Asian hotel group bought the property three years ago, an elephant camp was created - with a difference. Rather than simply offering elephant trekking, with tourists perched on wooden seats strapped to the elephants' backs, the company wanted the camp to have a conservation ethos. The day it was decided to look into a suitable project, John Roberts e-mailed from Nepal where he'd been working for the past five years in the Royal Chitwan National Park. He proposed an elephant-rescue programme in conjunction with the Thai Elephant Conservation Centre. There are under 2,000 elephants left in the wild in Thailand and their habitat is shrinking. The elephants working with mahouts, however, are in an even more precarious position. The elephant and mahout team traditionally worked in the logging industry. But, after the deforestation of massive tracts of land, commercial logging was banned.

Some mahouts sought work in illegal logging camps where the elephants were force-fed amphetamines so that they could work round the clock, which led to addiction and death. With no way of earning a living others were forced on to the tuk-tuk-clogged city streets. The mahouts buy bananas to sell to the tourists to feed the elephants. The mahout scrapes a living and the elephant is fed. However, the elephants suffer from stress and are frequently hit by cars. There's no point buying the elephants, Roberts explained, because the mahout would simply purchase another animal and the whole cycle would start again. It's a matter of education: for mahouts, and now, hotel guests.

The mahout-training programme is John Roberts' brainchild. Thinking back to his pony-clubbing childhood - when mucking out and grooming the ponies was as important as learning to trot - he came up with the idea of teaching tourists how to look after the elephants as well as how to ride them, providing the mahouts with employment at Anantara.

After their morning bath we had headed back to the elephant camp to learn the basic commands and practise mounting, dismounting and riding. Now, before taking them back to the forest, we were cooling off in the Nam Ruak. Slithering down the bank to the river, our broad bucking broncos rolled and splashed around in the water as we screeched with laughter and clung on until our knuckles ached: part rollercoaster ride, part Kate Humble moment.

Only 20 years ago this far-flung corner of Thailand was still off-limits to tourists, ruled by warring drug lords who controlled the rampant opium production. This lawless region, the point where the borders of Thailand, Burma and Laos meet, was nicknamed the Golden Triangle. Today, the Thai government has largely managed to eradicate opium production and the hill tribes who relied on poppy growing have been persuaded to farm alternative crops. Opium production is still prevalent over the borders in Laos and Burma, however.

Next door to the Anantara Resort is the impressive Hall of Opium museum. With fascinating black-and-white film footage, as well as an outline of the history of opium and its trade, it is more of an interactive exhibition. You should allow a good couple of hours to take it all in. The East India Company and CIA don't come out of it too well; if you're British or American you'll slope out of there pretending to be French.