Do you dream of visiting a natural ice cave within a glacier in Iceland? What exactly is an ice cave? Where can you find one? Why are ice caves blue and when can you visit the Crystal Cave in Iceland? Find out everything you need to know about ice caves and glacier caves in Iceland here.


What You Need to Know About Ice Caves in Iceland

  • Ice caves and glacier caves are not the same thing
  • Iceland's blue glacier ice caves are accessible between November and throughout March
  • Not all glacier caves are blue
  • Never try to access a natural glacier ice cave without a guide, as they are very dangerous
  • The natural ice caves are constantly changing, so they may look different daily
  • Ice caves can be white, blue or even black
  • Accessibility to glacier caves is highly dependant on weather
  • If an ice cave tour is cancelled you will get a full refund

Crystal Cave: One of Iceland's glacier ice caves

Iceland is home to multiple glaciers, which lend the landscape a multitude of exciting icy landscapes, including towering icy cliffs, crevasses, snow covered plains, glacier lagoons and natural glacier ice caves.

The natural glacier ice cave season in Iceland is in winter time, from the beginning of November until the end of March, with the exception of one glacier cave being accessible all year round. 

Additionally, there are some options to see ice caves (not glacier caves) all year round—although they are not as impressive as the glacier caves in Vatnajökull glacier.



Contents  
    4.1 - Crystal Cave
    4.2 - Blue Diamond
    4.3 - Waterfall Cave
    4.5 - Katla Ice Cave

What's the Difference Between Ice Caves and Glacier Caves?   
Crystal Cave is a beautiful ice cave in Vatnajökull glacier

When most people think of an ice cave they actually picture a glacier cave, such as the one pictured above.

But an ice cave is actually just any type of a natural cave that has some amount of ice in it year round; it does not need to be completely made out of ice.

However, a cave that is completely formed within a block of ice, such as a glacier, is a glacier cave. These two terms often get confused and people tend to talk about ice caves when they actually mean glacier caves. 

Glacier caves generally have that stunning blue colour of the ice that is so beautiful to look at, although there is also some blue colour to be seen within ice caves, mixed with the colours of the cave itself, which might be black, reddish or copper coloured.

Lofthellir is a lava cave with ice formations

Picture from Lofthellir ice cave

Before you book an ice cave tour, be sure you read the tour description and look at accompanying pictures so that you know exactly what to expect. Most ice cave tours in Iceland refer to the glacier caves that are found inside Vatnajökull glacier by Jökulsárlón glacier lagoon, but not all of them.



The entrance to Lofthellir cave is covered with snow

Iceland both has ice caves, such as the lava cave Lofthellir that's filled year round with magnificent ice sculptures and accessible during the summertime (from May to October), and natural glacier caves that can be entered at the height of winter only.

There are also some caves that have temporary ice sculptures, such as the lava cave Víðgelmir, and additionally, there is a man-made ice tunnel inside Langjökull glacier that you can visit all year round.



What is a Glacier?   

Glacier in Iceland

Iceland is home to many glaciers, the largest one by far is the Vatnajökull glacier in the southeast and east part of the country. 

Glaciers are made out of very dense ice, that doesn't melt away during summer. Parts of glaciers may melt and the glacier may shrink in size, or grow larger, but if the ice melts completely then the glacier seizes to exist and becomes merely a mountain.

Some glaciers in Iceland have already seized to exist, such as the former glacier named Ok.

Glacier lagoon at the tip of a glacier in Iceland

Glaciers only exist on land. Blocks of ice on sea or in water are called icebergs or ice sheets. Glacier lagoons are often found at the tip of a crawling glacier, such as the famous Jökulsárlón glacier lagoon.

Jökulsárlón glacier lagoon with auroras above

Another characteristic of a glacier is that it is constantly moving. It's their own weight that makes them move and deform, creating crevasses, moulins and seracs. Rivers may often run underneath or through glaciers where they shape the ice.

It is often said that the glaciers are crawling, as they slowly move over their surrounding landscapes. During this movement, they may often push sand and rocks from underneath the ground, which causes their circumference to be covered in black dirt.

The glaciers, as well as the glacier caves, will change in appearance daily, due to this constant movement. There is, therefore, never a guarantee that you will again see the exact same sight you once captured on a photograph; the glacier will have changed since the picture was taken.

Never attempt to go glacier hiking without a guide

Please note that glaciers, and glacier caves, are extremely dangerous. Never attempt to hike on a glacier or visit a glacier cave on your own.

The glaciers are full of cracks that may not be detected by the untrained eye, and people can easily fall dozens or even hundreds of metres into a glacier crevasse. The icy ceilings of a glacier cave may break and collapse if the temperature rises above 0°C and trap people underneath a heavy mass of ice—and glacier caves become even more dangerous and unstable during and after rainfall. 

But it's actually the road leading to the glacier caves that poses the greatest threat. For the last 6-700 metres before arriving at the caves, it's necessary to drive on black gravel and sand paths, that have the appearance of solid land, although they are actually on top of what is known as 'dead-ice.' 

Dead-ice occurs when the glacier stops moving and just melts on the spot. Underneath this dead-ice there may be a river flowing, and if travellers don't proceed with care, their cars could fall straight through this dead-ice.

Moreover, when hiking on a glacier or visiting a glacier cave, it is absolutely necessary to be equipped with the right gear, such as helmets, ice axes and crampons. This is why you should only explore glacier caves with a trained guide and on a tour.



Why is the Glacier Ice Blue?   

Sunlight breaking through into Iceland's ice cave

Glacier caves are famous for their vivid electric blue colour. As mentioned above, however, not all of them are blue!

The ice in a glacier is much thicker and denser than regular ice, such as the one you'll keep in your freezer or the icicles on your house. The ice is so thick, dense and old that it absorbs all colours of the spectrum except the colour blue, so that's the colour we see. 

The ice that is completely free of white air bubbles is the one that appears to be the most blue. Small bubbles of air reflect and scatter visible light, so when no bubbles are in the way, the light can penetrate the ice further and lose more red colour.

In ice, the absorption of light is six times greater at the red end of the colour spectrum than the blue end; so the deeper the light gets to travel into the clear ice, the bluer it becomes.

A darker shade of blue in one of Iceland's ice caves

However, the caves can also be white, turquoise, grey, brown or even black. Much like water has a number of different colours depending on daylight and its depth, so does the glacial ice.

Some glacier caves have openings that are covered by snow or are constantly in shade, so the sunlight doesn't reach the ice inside. Then, the ice will appear darker, or even black. Fresh or newly frozen snow on the ice's surface will give the ice a white complexion, but the ice can also contain a lot of sand, gravel and stones, giving the ice black patterns.

Glaciers will turn up the ground when they crawl forward, and since many glaciers in Iceland are situated on top of volcanic craters, there is often a lot of black volcanic ash contained within their ice.



Glacier Caves in Iceland   

Crystal Cave in Iceland

The most impressive caves in Iceland are the glacier caves. They form naturally when summer melt water carves long tunnels and caves underneath the thick sheets of ice.

As these are natural caves that melt and break down each summer, they are constantly changing and evolving. Each year the caves exist in different locations, varying in size and shape. Some years a few accessible caves are discovered, and sometimes none at all.

The glacier caves also change daily in size and shape and, therefore, each visit is unique. The picture above and the picture below show the same cave from a similar angle so you can see the difference between days, or weeks.

Glacier ice caves are constantly changing in Iceland

A sudden intense cold can make the cave stronger. The cold may freeze droplets falling from the ceiling, resulting in impressive icicles. It may also make the cave tighter and more difficult to access.

Iceland's weather is notorious for changing continuously, so the difference between days, or possibly even hours may be drastic.



Crystal Cave in Iceland's Vatnajökull glacier

A couple of days of mild winter weather may erode much of the cave; it can make it bigger; it may melt a hole into the ceiling, bathing the cave in sunlight or snow; and it may cause the cave to collapse or become too dangerous to enter.

Never try to enter a glacier cave on your own, even if you are an experienced hiker. In order to enter the glacier caves safely, you'll need to go with an experienced glacier guide who will decide whether or not the cave is safe to enter. 

A tour to a glacier cave is only ever cancelled to ensure your safety. If this happens, you will receive a full refund or be presented with alternatives such as a glacier hike or a snowmobile ride and then get a partial refund.



Crystal Cave in Vatnajökull Glacier in Iceland   

Crystal Cave in Vatnajökull glacier in Iceland

Since the caves in Iceland's glaciers are only temporary, it seems rather futile to give them names. But if many are discovered in the same location, each receives a descriptive name so that they become easily distinguishable. 

The Crystal Cave is the name given to a large ice cave in Vatnajökull glacier. It has appeared roughly in the same location since the winter of 2011-2012. There are of course high hopes that it will form again in the winter of 2017-2018, but only time will tell.

Crystal Ice Cave in Iceland

The Crystal Cave is carved out by a large glacial river each summer. This is the glacier cave most travellers have been to, as multiple guided tours take travellers there, due to its size and favourable access. The inside of the cave resembles a crystal dome, explaining the name.

The beautiful ice Crystal Cave in Iceland

In recent years, the Crystal Cave has been large enough to room 70-100 people at a time. It is located a little west of the glacier lagoon Jökulsárlón, which is the starting point for all tours leading to the caves in Vatnajökull glacier.

Close to the Crystal Cave, another smaller cave called the Dark Rubin has sometimes been accessible. The Dark Rubin is large enough to fit 30 people; it is completely dark, made up of black ice.



Blue Diamond Cave in Vatnajökull Glacier in Iceland 

The Blue Diamond Cave, a stunning glacier ice cave

The Blue Diamond Cave was the name of one of the glacier caves that appeared in Vatnajökull in the winter of 2016-2017. The Blue Diamond Cave had a gorgeous blue colour, like the rest of the glacier caves, but was much smaller than the Crystal Cave. Only 17 people would fit in the Blue Diamond ice cave at a time.

Arguably the Blue Diamond had an even more beautiful blue colour than the Crystal Cave, hence the name.

Natural ice tunnel inside a glacier cave in Iceland

The Blue Diamond was, in fact, a moulin cave (also known as a glacier mill). It was formed by snow, high up on the glacier, but not carved out by a glacial river like the Crystal Cave. A moulin is normally vertical, but the Blue Diamond was an exception since it was a horizontal. 

However, access to the Blue Diamond Cave was often possible even when the Crystal Cave was not accessible. This was because the Blue Diamond Cave was situated higher up on the glacier, where the temperature would generally be lower, but it also means that it was harder to access.

This cave, like all the others, has now disappeared and it's not likely to appear in winters to come.

Close to the Blue Diamond Cave the Black Diamond Cave was also accessible and could fit around 20 people. But it only had black ice inside and was not as popular with travellers.

The Waterfall Cave in Vatnajökull Glacier in Iceland  

Waterfall Ice Cave in Iceland

The Waterfall Cave existed both in the winter of 2015-2016 and the winter of 2016-2017. This large cave was safe to enter, even though a small river and waterfall ran through it.

This cave was formed by the river flowing into it, as opposed to running out of it. Out of all the glacier caves mentioned here, it's the only one that's situated East of Jökulsárlón glacier lagoon, by Veðurárdalur valley.

The ceiling was not very high, but the Waterfall Cave was rather sizeable. By following the small river you would end up by the small but picturesque waterfall seen above. Hopes are for an ice cave in the same location with a waterfall to be accessible again in the winter of 2017-2018.

Northern Lights Ice Cave   

The Northern Lights Ice Cave

Only accessible one winter, a few years ago, was the stunning cave that was named after the dancing auroras: The Northern Lights Cave. The beautiful lines in the ceiling of the cave were reminiscent of the Aurora Borealis.

All the ice cave tours would go to this cave when it existed, but unfortunately, it was just accessible for one year.



Glacier Cave by Katla Glacier in Iceland  

Glacier ice cave by Katla glacier in Iceland

The newest ice cave that has been found in Iceland is in the glacier of Katla, one of the most dangerous volcanoes in Iceland.

This glacier cave is darker than the glacier caves in Vatnajökull glacier and does not contain blue ice. On the other hand, it is more accessible from Reykjavík as the drive to get to the glacier is half of what it is to get to Vatnajökull. Additionally, this ice cave is accessible during summertime!

Black ice with a bit of blue ice in Katla ice cave in Iceland

Tours going to the glacier cave by Katla started in the winter of 2016-2017, but as the cave stayed safe to enter into the spring and summer months it has also been accessible throughout the summer of 2017.

Expect to see black ice when visiting this glacier cave, with small patches of light blue ice and white snow.



Man-Made Ice Tunnels in Langjökull Glacier  

Man-made ice tunnels inside Langjökull glacier

Lastly, the man-made ice tunnels in Langjökull have to be mentioned. These impressive tunnels have been dug right into the glacier, and even contain a chapel within the depths of the glacier!

A wedding photo from within Langjökull ice cave tunnels in Iceland

Wedding photo from Langjökull ice cave tunnels. Picture by Kristín María.

The space has also been used as a part of the Secret Solstice Festival, when concerts were held within the glacier tunnels.



The tunnels were created high on the glacier, in contrast to the natural ice caves which are normally at the edges of glaciers and quite unstable. The tunnels, however, are very stable and are accessible all year round. Inside you will be able to see the alluring blue ice of the glacier.



Glacier & Ice Cave Exhibition in The Pearl in Reykjavik

Perlan, or The Pearl, in Reykjavík hosts a glacier exhibition

Even if you're in Iceland at an unsuitable time for visiting the glacier caves, you can still learn a lot about them and get a feel of what they are like by visiting the newly opened Glacier and Ice Cave Exhibition in The Pearl in Reykjavík.

The Glacier and Ice Cave Exhibition is the first of its kind to be opened to the public. It is as a part of a larger exhibition named Wonders of Iceland which will also include a Planetarium, a Northern Lights Exhibition and a Land, Coast and Ocean Exhibition that are due to open in May 2018.

In the Glacier and Ice Cave Exhibition, you can visit the first indoor ice cave in the world, right in the centre of Iceland's capital city—and its accessible all year round.

If you're looking for something more to do in Iceland's winter wonderland, then check out the Best Winter Activites in Iceland!

Which glacier caves have you visited in Iceland? Tell us about your experience in our comment section!