Our guide, whose name escaped my slightly panicked mind (I’ll call him Fritz for the purposes of this story) hands out open-flame carbide lamps to about half of the group. There’s no electrical lighting inside the cave so this will be our only light. As the largest ice cave in the world, the Eisriesenwelt is 42km deep but Fritz informs us we will be venturing “only” 1km inside.

As we enter the dark, cavernous space the air suddenly turns chilly. We’ve been warned to rug up as it’s around zero degrees inside.

Our group forms a huddled conga and follows Fritz’s lead along the narrow walkway into the cave’s first chamber.

Thankfully it’s quite roomy inside. And stunning. Lit by the soft amber lamplight, the cave resembles an icy wonderland, its pristine walls sparkling like Swarovski crystals.

It just so happens that it’s also a tomb. As we move on, Fritz points out an urn sitting on a raised platform of ice known as the Von Mork Cathedral. It contains the ashes of Alexander von Mork, a pioneering cave explorer who led several expeditions into the caves in 1912 and was killed in action during World War I.

A vast network of tunnels and chambers, the Eisriesenwelt is what’s known as a dynamic cave, meaning the draughts of air flowing in and out cause ice to form in the cave’s lower levels during the winter. In spring meltwater drips down into the lower parts where it freezes and gradually evolves into the weird and wonderful formations we now see before us.

There are some amazing ‘ice sculptures’ in here, all of them hand-crafted by Mother Nature herself. There’s one in the shape of a giant jellyfish and another that resembles an elephant. And in the middle is the Posselt Tower, a huge, ice-solid stalagmite.

Every so often Fritz lights a magnesium flare, illuminating the frigid splendour of the cave to fantastic effect.

We have now traversed 700 steps into the deepest part of the cave – the Ice Palace. Fritz tells us that there’s 400m worth of rock directly above us and the claustrophobia starts to get the better of me again. Still, it’s only 700 steps back to daylight. And it’s a scenic route to boot.

Explore Salzburg

A Sound Of Music Tour

How do you solve a problem like Maria? Find out by taking a cheesy Sound Of Music tour of the film’s famous locations, including the Pavilion outside Hellbrunn Palace where Rolf chased Liesl around the gazebo; the gardens of the Schloss Mirabell featured in the Do-Re-Mi song; and Nonnburg Abbey, where the real Maria was a novice.

The Mozart trail

There are landmarks galore dedicated to the Salzburg prodigy. At No.9 Getreidgasse is his birthplace and childhood home, and No.8 Makartplatz is where he lived aged 17 until 24.

Hohensalzburg fortress

Perched on the rocky Monchsberg, the fortress was once home to the archbishop-princes who ruled Salzburg. Check out the state rooms or take in the view of the city.

» Alison Grinter travelled with Eastern Trekker (0845 257 8345).