Baikal: the very name fills Russian hearts with awe. And it is starting to attract pioneering tourists looking for an extreme wilderness experience

With savage winds whistling off the Angara River and a temperature nudging minus 40, Irkutsk at the dog end of winter is not a hard city to want to leave. It's not just that it's a world drained of colour. Nor is it the grey Soviet-era housing blocks and the grey pallid citizens scuttling to get inside housing blocks out of the cold. Nor is it even the nicotine shroud hanging over the city from the surrounding industry. Though God knows these things combined would test even the most sanguine of men.

No, what really hits you is the sense of isolation. Two thousand miles west of the Pacific, 3,200 miles east of Moscow and south of nowhere, stranded in Russia's great empty quarter, the Siberian city feels as if it is being punished, in exile. I had been there just 24 hours, but that was plenty.

Early the next morning, I headed east. Also in the minibus were a local guide, Alex, and five friends on holiday from Moscow. We rolled across the steppe. Mile after mile of flat, empty earth, punctuated by towns of small wooden houses, clustered around smoking, belching factories. It was a landscape seemingly coated in ash, the Siberia that Maxim Gorky called "a land of frozen chains and ice". Not a benign snowy landscape, but somehow cruel. Irkutsk may have been behind us, but its spirit wasn't.

The road rose gently.

"Wait, wait," Alex said. "Get ready. Here it comes."

We turned a corner, and the taiga forest of birch, fir and larch parted gently, like theatre curtains. The van fell silent as we stared ahead, mouths open. For beneath us, stretching away and framed by snow-capped mountains so perfect they looked like bad stage scenery, was a world as monochrome as the one we'd just left. But not grey. Nor burdened. But dancing in light, shimmering, blinding, like a giant diorama made from mother-of-pearl. For here was Lake Baikal; mystical, revered, sacred Baikal.

At 360 miles long and 25 miles wide, Baikal is more a sea than a lake, with ferocious storms that can whip up 15ft waves and swallow ships whole. From our vantage point, we could see huge spumes of water crashing against the land and angry swells and eddies swirling offshore. But staring closer, the water didn't move, the breaking waves hung frozen in mid-air, like a painting. And then an articulated lorry drove across the painting. Confusion.

"The lake gets colder and colder," Alex explained, "and then, usually in February, it freezes overnight. Whatever was happening on the water at the time, it's frozen like that until spring."

It was as if a wicked ice queen had cast a spell.

We drove down to the lakeside and, threading our way through the frozen breakers, walked a few hundred metres out onto the ice. Beneath our feet, the ice was two metres thick, but such is the purity of Baikal's water that it is as translucent as cut glass, allowing you to see down, past the trapped bubbles, to the kelp forests below. This induced a sense of acute vertigo, not helped by the symphony of bangs and snapping, like the sound of distant gunfire, as the ice shifted. This shifting creates a baroque pattern of lines in the ice, like the smoke trails of an acrobatic display team.

We met our first Baikal transport: five teams of Siberian huskies and sleds. They were tethered and barking like bronchial geese. The guide said they were friendly enough to stroke, but those ice-blue eyes and enormous teeth said something else.

After a very brief, and very Russian, safety talk – "hold on tight" – we loaded up and were off, slithering across the lake, the huskies seeking the snow-covered ice for traction and, when failing to find it, whirling their legs around like cartoon dogs who've run off a cliff and don't yet realise it. From my mushing position, I heard a car horn and turned to be greeted by a toothless man overtaking me in a Lada, using the lake, as locals do in winter, as an ice highway.

We stopped for lunch in a sheltered bay. Mischa, one of the holidaymakers, pulled out a bottle of vodka and buried it in the snow. "Please make a note of the fact that a Russian waited until noon for the first vodka of the day. I don't want to give the wrong impression of my country," he said, retrieving the bottle and dispensing its now gloopy, viscose contents into silver tumblers. "To Russia!"

"To Russia," we all replied and necked it in one. The food was brought out: salo (thick slabs of salted pig fat, served with hot mustard) and pelemi (meat dumplings in a hot, salty brine).

"To friends," Mischa said. My tumbler had miraculously refilled itself.

"To friends," we replied. Another bottle was retrieved from the snow. The dogs settled down for a long wait.

We stopped for the night in log cabins, about 20 miles further up the lake. There is no access here from the outside world apart from via the lake, and the valley where the cabins were nestled was called "Dark Fold", a place the sun rarely penetrates. The silence was immense. So harsh is it to live at the lake that along the 1,600 miles of shoreline, there are barely 80,000 inhabitants in fewer than 50 settlements.

I walked with Alex on to the ice, the lake like silver cloth under a brilliant moon. I asked him about Baikal and its special place in Russian hearts. He reeled off some mind-boggling statistics. It is more than 25 million years old, a thousand times older than any other lake. At over a mile, it is the deepest lake in the world. If you emptied it, it would take every river in the world flowing into it a year to fill. It contains more water than the five US great lakes combined.

To the shamans and indigenous Mongolian Buryat people, it is one of the most sacred places on earth. With 1,500 species of flora and fauna found nowhere else, including the mysterious nerpa, the only freshwater-lake seal, it has been dubbed the "Galapagos of Russia". But, he said, looking solemn, there are problems…

There was a call from the group. The banya was ready. Ah, yes, the banya, what the Russians call a place for physical and moral purification, and in England we call an S&M club. We stripped and donned silly felt triangular hats to protect the ears. Then, to cries of "lyogkogo para" (may your steam be easy), into the parilka, the steam room. One of the guys poured a torrent of Baikal onto the coals and, despite my hat, within seconds my ears were melting and my eyelids peeling back over my head. To the sound of laughter, I ran out screaming, clutching my head, into the snow, where I rolled around like a man on fire trying to put himself out. Which, in effect, I was.

Alex then very kindly beat me within an inch of my life with rough birch twigs. "When you have lost all feeling in your body, you are done," he said. A week later, in London, I could still see the welts.

The next day we took a Hivus, a hovercraft adapted for ice and named after one of the many Baikal winds. The drivers expertly weaved around the frozen whitecaps and through the troughs, getting it wrong occasionally, when we would take off a wave-shaped ramp and become airborne, landing with a crash. Then we came to a smooth section, obviously in the lee of the shore when the freeze arrived, where the craft could really fly – 50, 60mph, outside the window a blur of white.

I took Peter Thomson's superb book, Sacred Sea, from my bag and started to read. Thomson travelled from his native Boston to Siberia in 2000 on a quest to mend a broken heart. He ended up giving it to Baikal. An environmentalist, he describes how the lake's ability to purify itself is down to one creature, an endemic microscopic shrimp called epischura baikalensis. This army of zooplankton vacuum cleaners have, for millions of years, sucked Baikal through their digestive tracts, filtering bacteria and decomposing plants – and tiny specks of pollution. So efficient are they that it's said that corpses, human or animal, are never recovered from the lake – the epischura consume any organic matter in hours.

But their ruthless cleaning routine was not designed with man in mind. Like an alcoholic believing in the invincibility of his liver, the Soviets put Baikal to work: a vast paper mill was built on the southern shore; hydroelectric dams were constructed to power the Soviet industrial machine, raising the level of the lake; air pollutants from the Irkutsk/Cheremkhovo industrial corridor rained down on its pristine wilderness.

So the epischura poison themselves, the olmu fish eat the epischura, and the nerpa, bears, raptors and humans eat the fish. A Unesco designation in 1996 drew attention to Baikal's plight, but a recent study found the nerpa now among the most toxic seals on the planet. And all this in just half a century. It is, as Thomson says, "the nasty irony in Baikal's stupendous self-cleansing act: extraordinary pure water; extraordinary contaminated animals". Put bluntly, if the epischura dies, Baikal dies.

The Hivus landed at the town of Khuzhir, on Olkhon, an island halfway up Baikal's western shore that's of sacred significance for Buryat shamans and Buddhists. In the harbour, rusting fishing boats and hulks, like the exposed carcasses of dinosaurs, lay trapped in the ice. We walked up the main street passing incurious Siberians and stopped off at a house to buy some olmu, the lake's staple food fish, from a babushka. We walked on to a lookout, where, beyond a tree draped in prayer flags and festooned with puja offerings to the spirits – kopeks, shoes, sunglasses, lighters – we see the Shamanka Rock, connected to the shore by a narrow isthmus, a place of veneration for all Baikal and Mongolian shamans and Buddhists.

There, we sat and ate lunch, in a biting but exhilarating wind: the olmu, eaten as you might a banana, by peeling back the skin and biting into the flesh, followed by rasstegay (olmu pie), and ukha (fish soup. No prizes for guessing which fish). All washed down, of course, by vodka.

"To adventure," said Mischa.

We slid down the icy slope to the rock and scrambled up the sheer face, into the sacred cave, home of Baikal's spirits.

"To the Baikal spirits," said one of the guys.

It was unclear whether we should have been drinking vodka in the most sacred cave in the Shaman world, but we toasted enthusiastically. Judging by the vodka bottles on the floor, there'd been a lot of toasting recently.

Back in the Hivus, we headed further up the lake's Maloe More, or shallow sea, passing fishermen dragging huge nets through immense holes cut by chainsaws. Then we stopped to watch some locals fishing in more traditional fashion, with line and hook through a corkscrewed hole in the ice.

We rounded a headland. The ice became rough, contorted into fantastical shapes, like tank traps on a Normandy beach. The Hivus got stuck fast. Had we angered the Baikal spirits? The two Russian drivers got out, scratched their heads, and smoked furiously. Then scratched their heads some more. Then they got a tiny foot pump, as you might use on a lilo, and started pumping.

While we were waiting, we went for a walk. Above us, the insipid sun, with an orange corona, looked like something out of a sci-fi film. But then the sun went out as – seemingly from nowhere – a blizzard descended. It felt apocalyptic. Just in front of us, a huge gash had opened in the ice, and we stood there, on the edge, staring into the icy water, feeling suddenly very vulnerable. There's a saying that a dip in Baikal's waters will add 25 years to your life, but I think they might have got that the wrong way round.

There was the familiar sound of Baikal shifting, creaking, cracking, groaning. But then a quite different noise. We all fell silent, like submariners listening for the sound of an enemy ship. A rumbling, gradual at first, built and built, coming from the depths of the earth, until the ice started to twist, wobbling like jelly. We wobbled with it, trying to keep our feet, dancing a drunken jig to a deafening roar of such elemental anger as I've never heard before. It was over in five seconds. I had never been so terrified.

Mischa produced the bottle from his bag and poured.

"To Baikal! To earthquakes!" he said. "To Baikal! To earthquakes!" we replied.

Some days later, we were back at the southern end of Baikal, where the Angara flows out of the lake. Across the water sat the paper mill. Some 50 miles upwind to the west, the smoking chimneys of Irkutsk.

At the head of the river, in the middle of the channel, stood a rock thrown, according to legend, by Father Baikal in a futile attempt to stop his daughter, Angara, fleeing to join her lover Yenisei, the great river to the west. These days, thanks to the dams, only the very tip of the rock is visible. Baikal lost his daughter. Whether we lose sacred, beautiful Baikal, only time will tell.

Essentials



Mike Carter travelled with KE Adventure (01768 773966; keadventure.com ), whose new nine-night Lake Baikal in Winter package costs £1,895, including all activities – dog sledding, hovercraft trips, snowmobiling and trekking – guides, full-board accommodation and transfers. The next departures are 14 February and 10 March 2010. Flights from London to Irkutsk cost from £470 with Aeroflot (020 7355 2233; aeroflot.co.uk ).