When dawn breaks in the Alps, a soft orange light rolls across Switzerland, silhouetting peaks and splashing the snowfields pink. The Eiger is first to concede to the sun, then the Matterhorn: the looming towers of the Grandes Jorasses hold out for seconds before, in an instant, a vast triangular shadow projects on to the lowlands of France. It will be hours before the valleys are lit, but here on Mont Blanc morning has begun. Five hundred metres below the summit two Italian climbers walk to the Vallot Hut - undoing their harnesses to greet the new day in Western Europe's highest lavatories.

A century ago there were seasons when only one party made it to the top of Mont Blanc. Nowadays 30,000 people attempt the mountain every summer, most on organised tours. For less than £1,500 companies will guide you, acclimatise you, and - as long as you are fit enough - get you to the top.

Jean-Marc Peillex, the Mayor of the Mont Blanc region, has long fumed about overcrowding on the slopes. “The legendary climb to the peak of Mont Blanc is becoming a piece of cut-price, consumer goods,” he says. In 2006 he launched a failed campaign to lobby for a paid permit system, but was more successful in plans to clean up the slopes - including building the conveniences close to the summit to which the Italian climbers are headed.

But the mountain remains far from tamed: this month eight people died in a massive avalanche as they began their climb. Retrieving their bodies is too dangerous, so they will lie under ice until their glacial coffin spits them out.

As the sun dazzles out the last of the stars and our zig-zagging line of head torches becomes a trudging snake of black dots, patches of yellow and brown snow testify that the lavatories have not been wholly successful. Inside the Vallot Hut itself, a minuscule unmanned refuge at 4,360m, there is a smell of rotting fruit. In places the floor is completely obscured by litter: the foil detritus of survival blankets catch on crampon points to spread around the mountain.

Today, as with most clement days on Western Europe's highest mountain, 400 people will attempt to reach the summit. Uniquely in the Alps, the majority are guided - with little or no climbing experience. Their journey began 24 hours earlier on the 7.25am funicular train from St Gervais, with its mix of early-rising tourists and eager Alpinists. Wizened climbers with mountain beards and battered ice-axes share seats with parties of Japanese in shiny clothes and top-of-the-range, barely used, equipment. One man is dressed all in Lycra, a stripped-down backpack and small bag of energy gel the only signs that he is climbing a mountain rather than going for a cycle ride.

At the end of the railway line, 2,500m below the top, we are met by a man in a green tourist-board fleece. “Bonjour. Vous allez à Mont Blanc?” he asks. Some on the train are just following the path part of the way, but for the rest of us - perhaps as many as 100 - he wants to check that we have made sleeping arrangements.

In 2003, when a hot summer caused the snow slopes to destabilise, teams of his colleagues waited at the station with a different purpose, persuading climbers that ascents were too dangerous - effectively closing the mountain. The thaw that year exposed layers of accumulated human waste like tree rings in the glacier, disgusting authorities and leading to a rethink on the mountain.

Elsewhere a snobbery persists. In the climbing bars of Chamonix, where the mainly English clientele plan their ascents over French lager, Mont Blanc is considered a useful means of keeping the rest of the Alps free for the proper climbers. It may be the highest in the range, but it is also one of the easiest: a snow plod, a trudge, a walk. It is ignored and reviled. Last year a group of climbers took a full working spa bath and hot tub to the top, later issuing an apology to those other Alpinists who had “hoped to be alone on a virgin summit”.

In a collective 15-20 summers spent in the Mont Blanc range, my three climbing partners and I had never considered the mountain: why would we waste two days of our holiday on something that is no more than a test of endurance, albeit one that requires crampons, ice-axes and a rope? Yet our colleagues on the ascent had clearly been training, and it is difficult to remain sniffy when people in their fifties and sixties zoom past as you pant up the hillside. Sue Warwicker was part of a group of ten who eventually made it to the top. “We hadn't climbed before, but my husband said he wanted to do it for his 50th birthday, and so we started preparing,” she said.

By the time we reach the Grand Couloir, the first major obstacle, we are near the rear of the pack. The 700m-high50m-wide couloir, or gully, cuts across the path. As soon as the first sun hits, rocks come unfrozen from the cliffs above and tumble down at deadly speeds. We take the only way across - a lumbering 20-second dash while waiting climbers shout warnings from the sides.

On our descent the next day a man fell the entire length of the couloir to his death, landing where the path crossed. Within minutes the ultra-efficient Chamonix mountain rescue had airlifted off the body, so that by the time we reached the base - meeting other climbers speeding to the top - there was no sign that anything had happened.

The couloir splits the rest of the mountain from the Gouter Hut, where most climbers on this, the most popular route, will spend the night before heading for the summit. At 3,800m, on the edge of a huge cliff, the hut is spectacular. The front windows have unobstructed views across the valley; the back ones are snowed up, facing into a glacier. Inside the prefabricated walls it is a bustling, sweating, freezing mess. A British climber, stopping briefly before descending lower, derisively calls it a zoo, as she sits at a crowded table loaded with sleeping Alpinists and thawing piles of climbing equipment. But given its isolation, it is incredible that it functions at all.

Claude Barnier, the hut manager, is in the toilets when we arrive. “Parlez-vous Anglais?” I ask. “Pas aujourd'hui,” he shouts back from a cubicle. “I'm cleaning merde.” Mountain refuges are the distillation of a nation's most persistent stereotypes. Swiss refuges are impeccably clean. They have hi-tech composting toilets, charming rustic woodwork and flags displayed with a prominence that is just the wrong side of disquieting. German huts are jolly and hearty, with a dozen different schnapps and a beer-hall atmosphere. The Gouter Hut, on the other hand, is grimly purposeful, fighting a running campaign against its smelly occupants. Its lavatories are functional - just a row of holes above a steep 1,000m drop.

Later I find Barnier sweeping the dining hall, where 120 climbers eat every night. “This is the hardest job in the Alps,” he says. “There are too many people who don't book, who turn up and sleep on the floor. There is nothing we can do with them.” The hut has to obey two conflicting laws. It has the same fire regulations as a hotel, but as a mountain refuge it is forbidden from turning anyone away. In practice, the latter duty wins, and on busy nights the dining-hall floor is covered in climbers unable to find space. For most of the day it is also a rare fixed passing point for those about to ascend and those on their way down. A group of young Irish climbers sit on a table beside us. Preparing to go up the next day, they had trained by taking the ferry across to climb in Wales. “We are quietly confident,” Padraig Looby says. “We did Snowdon a while ago. That was the highest, and so we thought we had to branch out.”

What I hadn't said in my chat to Barnier was that we were precisely the sort of climbers he was complaining about. An independent party, we found it impossible to make a reservation (guides had booked up months in advance), so we carried a tent and joined a small party illegally camped on snowfields above the hut for a windy, shivery, sleepless night at altitude.

Accommodation troubles are not the only source of tension between climbers and guides. There is a minority culture, notably among French guides, of breathtaking arrogance, bordering on recklessness. On narrow rock routes, friends have had guides rush their groups over them, under them, around them. They have had their own protection unclipped and replaced, their ropes used without permission. One even had a young guide attach a client to his rucksack. On one climb I had to tell two climbers that their guide was endangering their lives, after I watched him leave them unprotected above a perilous drop in his haste to finish the route before his next job. The clients, who had never climbed before, did not even appreciate the problem.

But the next morning we are united - guides, clients and climbers alike - in a convoy of head torches up an endless snow slope. From 2am until dawn we climb. Some, but not many, turn back. Our progress slows as the altitude rises, until near the top we rest as often as we walk. On the ridge opposite a smaller chain progresses through the night, to converge with us at the summit. They are on the Cosmiques, or “three summits” route. A day later, and the route was closed: eight people dead and the mountain rescue taking the rest off by helicopter. The scariest aspect for us was that they did nothing wrong. Part of the reason why we climbed so early was because that was the best time to avoid avalanches.

And then, at 8.30am, there is suddenly nowhere else to climb. We take a photograph on a crowded summit, before beginning the long walk down. The climb was not the Alpine solitude I would have liked, yet I disagree with the Mayor. Mont Blanc is crowded, but only compared with other Alpine peaks. If Ben Nevis can take hundreds of thousands of visitors a year then this mountain, at four times the height, has plenty of capacity, if it is organised properly. I'm just not sure it is for me. Mont Blanc is a challenge, a test you set yourself. Many of those who reached the summit will some day, or have already, run a marathon. I won't.

A few days before the climb we acclimatised on a small rock pinnacle across the valley: the Aiguille de la Persévérance. From the top of Mont Blanc, two vertical kilometres higher, it is barely noticeable. But it was a full day's climb, mainly on rock, and in the entire ascent we saw four other people - two roped together on an opposite peak. It was a beautiful route.

If I ever have children, take them to Chamonix and point to Persévérance, they will be unimpressed. If I point to Mont Blanc - still majestic, still magnificent - well, that is impressive.

Which is, perhaps, the point.

The world's despoiled gems

Uluru Each year thousands haul themselves up 340m to the top with the aid of a chain fence. Australian Aboriginal communities, to whom the rock is sacred, have always been uneasy with the hordes and have tried several times to ban all climbing.

Everest Conquering the world's highest rubbish dump is no longer an achievement. Its first 150 climbers did so in a 30-year period, but since then people have skied, snowboarded, paraglided and got married on it, and a helicopter pilot claims to have landed on top.

Machu Picchu Peru's leading tourist attraction earns the nation more than £3 million a year and is a World Heritage Site, but Unesco is considering listing it as endangered because of the damage caused by up to 1,500 tourists a day

Snowdon With 500,000 tourists a year and work continuing on a delayed £8 million visitor centre, Wales's highest mountain is busy. Trampling feet and mud have widened paths to 25m, and EU funds help to pay for 32 workers to tackle the effects of erosion