Why you need to book a tour of the iconic Game of Thrones 'Dragonglass Cave' asap

Climbing out of a monstrous truck on 46-inch wheels, I am met with a vista of black sands and moss-capped mountains. We’re just a short ride from the nearby Icelandic town of Vik but the view is otherworldly – a sci-fi novel come to life. Ahead stands a massive glacier, proud and pristine. It appears completely immovable, but this gargantuan mass of ice is practically alive.

I have come to explore the ice caves at the foot of Mt Katla, an active volcano partially obscured by the Mýrdalsjökull glacier. Though I occasionally work as a glacier guide myself, it has been two years since I’ve visited this one in particular. In addition to today’s guide, Trym Norman Sannes, I am joined by Icelandic nature expert and photographer Ása Steinars as well as an Argentinian friend, Sol Sarratea, who is seeing a glacier in person for the very first time. As we approach the icy giant, Sarratea is unselfconsciously awestruck, snapping Mýrdalsjökull from every angle with her camera – a common reaction for a first-timer. “It’s so beautiful but still so far away,” she exclaims, pointing towards the glacier’s snow-capped top. We’re only about 100 metres out. “What are those black hills? And those green patches?” Her eyes widen even more. I inform her that the black patches are sand and ash from the volcano. The green is in fact blue ice, shining through from beneath the surface. Iceland’s landscape appears alien to those unfamiliar.

Contrary to common imagination, glaciers are not white or transparent. Instead, white sheets of snow, luminous blue ice and jet black ash interlace in a mosaic of towering ice blocks. Droplets of water glisten in the sunlight. Roaming between these natural castles of ice, we take in contrasting textures, noting the air bubbles trapped within the solid slabs of blue. One block boasts an almost impossibly perfect gradient of clear ice to pitch black while another is striped black and blue. A third is covered in holes – an abstract pattern drawn by the small rocks embedded within. It appears as a frozen image of the ocean, with waves and currents trapped in time.

In many ways, the glaciers are a snapshot – history can be read through their seemingly arbitrary appearance. Ash from volcanic eruptions from a bygone era becomes trapped within the ice, leaving broad brushstrokes of black. In analysing the glaciers, scientists can determine which eruption the ash came from and subsequently read into weather patterns from the past several centuries.

“Katla is due to erupt soon. It erupts every 90 years or so, but the last big eruption was in 1918, so we’re overdue,” Norman Sannes, our guide, informs us. He rightfully notes that the area must have changed significantly since my last visit. In recent years, Iceland’s glaciers have lost about 40 square kilometres annually and it is feared that the country may lose all of its glaciers within the next two hundred years due to climate change. The change is so rapid that it is glaringly visible to the naked eye. “There was a really big and popular ice cave here last season, but it collapsed a few months ago,” says Sannes.

Collapsing ice caves are not the only risks here. Each year the glaciers gather snow in the wintertime, which turns into more ice before melting down during summer, like an over-frosted cake with sugary liquid dripping down the sides. When the water eventually freezes, it becomes heavy, meaning the brittle top can easily crack. The hazard of falling ice makes traversing the glaciers dangerous business, which is why a visit necessitates an experienced guide. Thinning ice bridges and rooftops can collapse in an instant and fluffy snow can disguise dangerous cracks. The rock-hard ice can be both slippery and sharp as glass.

Luckily Sannes, a Norwegian who has made Iceland his home, knows the area well and regularly leads trips to the region for Troll Expeditions. Still, he’s had his brushes with danger. “One day I just decided to go for a walk since it was a nice day. I was by myself, and I didn’t have glacier gear with me, which was of course stupid. I walked along the edge of the glacier and then I came across these three caves that are close to one another,” he recalls. “On the way back, however, there was some fresh snow and the ice broke underneath me and I fell into a pool of ice cold water. Since I didn’t have any gear I had nothing to get a grip on the ice to pull myself out, and I thought to myself that this is where I would die.”

“What happened?” We ask with rapt anticipation, even though it’s perfectly clear that he made it out alive. “I remembered that I had my car keys in my pocket, so I managed to get a grip on the ice with them and pull myself out,” he says, adding with a chuckle that his wife was less than pleased. “It was a month after our daughter was born.” He and his wife named their daughter Katla.

The experience hasn’t dented Sanne’s fascination with the area and today he’s leading us to a fresh crop of ice caves that he’s recently discovered. The ice that forms these caves is filled with layers of ash, granting them a blackish hue, with glimpses of blue that peek out from between the cracks. The more compact the ice is – with fewer air bubbles – the more vivid the blue appears. If the sun has been shining on the surface for a while, a white crust for ms, obscuring the colours within. I ask Sannes if tourists are ever disappointed by the look of the ice if they arrive on a particularly sunny day. “Sometimes, but I explain to them that they’ll have to accept that they’re visiting a natural attraction that is constantly being reshaped by the elements,” he says.

This is the magic of each visit – you never quite know what you’re going to see on any given day. Meanwhile, the shining sun provides an alternate benefit – its rays make the ice and water glisten like diamonds. In the summer, with Iceland’s nearly endless daylight, you often catch this shimmering ice. Today there are blue skies, followed by a sunset so spectacular even the most jaded iPhone owner would be compelled to take its photo.

“Should we go take a look at the collapsed cave?” Sannes asks the group. Where once stood the glacier’s grandest cave we now find ice columns rising from black sands. An impressive water fa ll plummet s down from many metres above. The entire scene is bathed in a golden glow from the setting sun. It’s hardly a surprise that Katla served as inspiration for “The Wall” – a monstrous barrier dividing the north from the south in Game of Thrones.

Today there are 269 named glaciers in Iceland, down from 270 in 2014 when a glacier named Ok ceased to exist. While a visit to Katla, or any of Iceland’s stunning glaciers, is an extraordinary experience, it is also an indisputable reminder of how our world is changing. While Katla holds history within its icy walls, its future is far less certain.