This glacier repeatedly melts and freezes in a new form. The results are stunning.
If you follow "Game of Thrones," you know some scenes call for some pretty remote — not to mention freezing — locations.
They look pretty majestic on screen, but one ice-cold location in particular looks even cooler in real life.
This is Vatnajökull, the largest glacier mass in all of Europe.
Pretty spectacular, right? I mean, look at this place!
These incredible images were taken by British photographer Mikael Buck, who was the first to capture these stunning caves from the inside using a special sensor technology.
And he had to go through quite the trek just to get there.
"Accessing the best caves requires a two-hour hike each way over the glacier. To do this, you need to rope up to your hiking partners, carry an ice axe and wear crampons," Buck wrote in an email.
A local guide, Einar Rúnar Sigurðsson, made the journey possible and helped Buck go deep into the glacier in order to access the most impressive ice caves.
Because the caves can only be accessed during winter — daylight hours are limited — they had to race time to get the images Buck wanted and get back while it was still light.
But when Buck actually set foot inside the ice caves, it was pure magic.
"Entering the caves for the first time, you step into a dark hole and suddenly you are in an alien landscape. It was unlike anything I've seen before and the colours are just as vivid in real life as in the images," wrote Buck.
"The shapes and textures where the water has slowly eroded parts of the ice are amazing. If we had the time I could have happily spent hours in there staring at all the cracks and crevasses."
The caves presented some unusual challenges though.
"Inside the ice caves themselves, things can get very claustrophobic," Buck added. "At one point I was on my hands and knees crawling under the ice above in order to get to another part of the cave."
"Game of Thrones" filmed in the surrounding areas and not inside the actual caves (maybe because they would look better for an alien movie). But even if they had, the cave they would've shot then is different from the way it looks today.
You see, the appearance of Vatnajökull is constantly changing.
"Each summer, the ice moves and new caves form and old ones collapse and are never seen again," explained Buck. "The caves themselves are formed where water runs off from the surrounding slopes and into the sides of the glacier."
The sheer magnitude and beauty of these ice caves put things into perspective for Buck.
"It was an awe inspiring trip and an experience I won't be forgetting in a hurry," he said.
"As with any trip to somewhere so wild and remote, the concerns of life in the city and the world of work seem pretty trivial on your return."
As beautiful as these morphing formations may be, they may not be around forever.
Glaciologist Oddur Sigurðsson has been very outspoken about the significant shrinking that Icelandic glaciers have undergone in the past 20 years. The culprit? You guessed it: climate change.
"The caves themselves are not formed as a result of climate change, but the glacier itself is rapidly retreating," noted Buck. "Our guide pointed out the distance the glacier had retreated in his lifetime and it was quite staggering."
At the current rate the world is going, these glaciers may be completely wiped out in 200 years.
That means we would lose one of Earth's most amazing natural wonders just like that.
These images are breathtaking, but they also paint a bigger picture.
Fortunately, some necessary steps are being taken to save these marvels for future generations. The Kolviður Fund, for instance, has made it their mission to reduce CO2 emissions in Iceland by improving their forest ecosystems. By planting more trees strategically, they hope to offset the CO2 emissions generated by cars and flights and preserve the glaciers.
And works such as Buck's photo series are able to shine a light on this important cause. By spotlighting just how magnificent these remote locations are, people can better understand their value to the world and just how worth saving they really are.
So yes, winter may be coming. But in this particular case, we hope it's here to stay.