Chalet Petit Tinqueur - Chamonix, France

Doing the famous Vallée Blanche

Doing the Vallée Blanche is not so much a skiing achievement as an incredible day-long, high-mountain experience.

In less than half an hour, you ride by cable car from 1030m to 3777m, high up towards the summit of Mt Blanc. The air is noticeably thinner and you're pitched straight into another world - one that consists of year-round snow, glaciers, crevasses, seracs, crampons, ice-axes and spectacular cliff-faces. It's quite unlike anything you've ever seen before.

Welcome to the high-mountain terrain

Make no mistake - this is unmarked, unpatrolled, dangerous high-mountain terrain that demands the utmost respect. There are no pistes and it shouldn't skied without a guide or at least a very experienced, very well-equipped group. But it's not difficult to ski (or board) and is something that every comfortable intermediate or above should do if they visit Chamonix...

Take your time to acclimatise at the Aiguille du Midi - it sometimes takes a while to get used to the thin air. There's a snack bar, restaurant, toilets and viewing terraces to take in the staggering 360 degree views. It's a bit like a James Bond villain's lair, with tunnels and lifts inside the mountain. In summer, you can take the Panoramic Mont-Blanc bubble lift across to Pointe Helbronner above Courmayeur. This amazing 1-hour ride over the Glacier du Géant is breath-taking in every sense, as you stare right down the bottomless crevasses from several hundred metres up.

Ah, the lovely arête...

The start of the Vallée Blanche is arguably the most nerve-wracking bit of the whole thing - negotiating the arête (snow/ice ridge) that leads out from the Aiguille du Midi. This short ridge has a fixed rope and a path dug into the snow, but guides generally rope groups of guests together. Although people rarely do slip, the consequences would in all likelihood be fatal if you weren't roped together to your mates...

Once you're past the arête, you have several options for the descent. The Classic Route is the one taken by most guided groups, dropping down across the Glacier du Géant and then looping round onto the Mer de Glace (literally the 'sea of ice'). Alternative routes (like the Envers de Plan) are for advanced skiers only.

Most of the classic route involves fairly undemanding skiing/boarding and is well within the capabilities of an average red-run skier. There are a couple of steeper spots, where the glacier funnels down to the Seracs du Géant and breaks into an ice-fall. But otherwise, it's a surprisingly gentle descent and one that gets skied into an almost piste-like state.

Out of this world

It really is quite extraordinary to find yourself just yards from blocks of ice the size of a large house, skiing between crevasses that disappear out of sight, surrounded by rocky cliffs that rise thousands of metres high. The colours are extraordinary, too - the bright white of the snow, the greys and browns of the rock, the blues and silvers of the glaciers and ice.

For most groups, it's a day trip and you'll have brought a packed lunch. The Salle à Manger is a popular spot to stop, where you can look back at the seracs from a safe distance. The guide will usually point out the famous peaks - the Drus, the Aiguille Verte, the Grandes Jorasses and others. Each one seems to outdo the previous for sheer, jaw-dropping drama and beauty.

After a refuelling stop here, you carry on down the Mer de Glace to Montenvers, where you can take the old rack-and-pinion mountain railway back down to Chamonix. When snow conditions are good, you can even ski right back to town, making the whole journey not far off 25km. It's a trip you'll never forget...

Vallée Blanche under moonlight in 2000

Yep, you heard it right. Back in 2000, I was lucky enough to do the VB under the March full moon. If you thought it sounded spectacular enough in daytime, magnify that 100fold to get an idea of what it's like to do it at night under moonlight...

You catch the last cable car of the day, then watch the sun set from the Midi. After crossing the arête at about 6pm, you bear around to the right and head towards the Refuge des Cosmiques, one of the larger high-mountain refuges around Chamonix and a staging post for many folks climbing Mt Blanc or ski touring around the area.

After dinner, a few drinks (and maybe even the odd funny cigarette - no inhalation, of course...), you set off at about 10pm. I remember counting up the number of layers I had on - 7! It was FREEZING - I've never been in such cold before. You soon warm up, though.

You might think it would be hard to see where you're going. But not in the slightest. With the light of the full moon bouncing off the snow, the night sky was actually a dark shade of blue, not black. You could see everything.

I can try to describe here what we saw and what the experience was like. But it won't ever come near to doing it justice. Even in daylight, the terrain up there is like being in another world. Switch the lights off and replace them with a silvery moonlight and it's just utterly, utterly extraordinary. If you ever get the chance in your life, DO IT.

Of course, by the time we reached Montenvers, there were no trains running back down to town. So we had a bit of a trudge down the forest track (when the head-torches came in useful among the trees). We got back to town just before last orders at the Chambre Neuf, clunking into the bar in all our ski gear feeling like supermen. It was the end of one of the most amazing things I've ever done in my life...