The Vallée Blanche in Chamonix is one of the world’s most spectacular off-piste ski descents.

It starts from the Aiguille du Midi cable car – Europe’s highest at 12,600ft – and runs for 14 miles across the cascading snow-covered glaciers of the Mont Blanc massif mountain range.

It is unmarked, unmaintained and unpatrolled, so not for the faint-hearted but something most intermediate skiers can tackle if accompanied by a guide.

Jean Franck, the sixth generation of his family to work as a Chamonix ski guide, met us, armed with crampons, ropes, harnesses and avalanche transceivers.

The cable car soon whisked us up to the top of Mont Blanc, the closest you can get to the summit of Europe’s highest peak without hiking or climbing.

The view across miles of snowy peaks spanning France, Italy and Switzerland was breathtaking – as was the lack of oxygen in the air.

We followed Jean Franck through an icy tunnel leading out on to the mountain. Before us was a sign saying “Skiers Beware” and the narrowest of snowy ridges with a near-vertical drop on both sides and just a simple rope fence to cling on to.

He helped us strap crampons on to our boots and roped us together in a long line and we inched our way along the 330ft ridge, clutching the rope and trying not to look down.

It was nerve-racking but after about 15 minutes we were relieved to reach a wider, flatter part of the mountain where we clicked in our skis.

Whizzing through the silent, remote valley with not a chairlift or another skier in sight, we experienced a rush of adrenaline and a real sensation of wilderness. 

All around us were magnificent glacial formations sparkling in the sun and on the craggy mountain rocks. After a couple of hours, we reached the Refuge du Requin, a simple stone building which offers overnight stays to skiers and climbers throughout the year.

There we enjoyed a hearty lunch of soup and pasta. In the afternoon we stopped off to explore amazing ice caves deep inside the glaciers and ended our adventure on a funicular train that took us, exhausted but elated, back into Chamonix.

There, over hot chocolate and beers, we reflected on an epic life experience that we’d never forget.

The usual teenage nonchalance from Millie and Alex was replaced with a proud sense of achievement and awe – we had challenged our fears and reaped the rewards.

Back at our chic apartment complex, the newly built Le Cristal de Jade, we soothed our aching limbs in the pool, sauna and steam room. 

We then headed out into Chamonix’s picturesque town centre where upmarket boutiques and gourmet restaurants nestle alongside rustic burger joints and lively bars.

The previous evening we had gone along with teen demands for burgers and tacos at the highly recommended Monkey bar. But tonight we bagged a table at Le Cap Horn, where the unusual mix of sushi, seafood and traditional regional dishes wins high praise in the Michelin guide.

While extensive off-piste arenas satisfy the more extreme skiers, there is plenty for beginners and intermediates, too, especially at family friendly Les Houches on the outskirts of the resort.

It’s also a short drive through the impressive seven-mile long Mont Blanc Tunnel to Courmayeur in Italy, where we skied for the day and enjoyed a delicious fresh pasta lunch in one of its renowned mountain restaurants. After a week of adventure in the snow, Chamonix is now undoubtedly one of our favourite ski resorts.

An apartment sleeping four people at Le Cristal de Jade apartments (mgm-hotels-residences.com) starts from about £1,312 per week from December 2017 until April 2018.

For further information on Chamonix and hiring a ski guide, visit chamonix.com and chamonix-guides.com.