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The Ultimate Guide to Ice Caves in Iceland

The Ultimate Guide to Ice Caves in Iceland

Verified Expert

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

Crystal Cave: One of Iceland's glacial caves.

  • Ice caves and glacier ice caves are not the same things 
  • Iceland's blue glacier ice caves are accessible between mid-October and throughout March
  • Many operators do not start ice cave tours until November
  • 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 dependent on weather
  • If an ice cave tour is cancelled you will get a full refund

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.

But not all ice caves are the same, and the super stunning ones are in fact natural glacier ice caves.

The natural glacier ice cave season in Iceland is in wintertime, from the mid-October until the end of March, with the exception of two glacier caves which are 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 blue glacier ice caves in Vatnajökull glacier. 

What's the Difference Between Ice Caves and Glacier Caves?

Ice caves is a word for caves that have ice in the year round, not just glacier caves.Photo from 2 Day West Coast Tour | Snaefellsnes, Lava Caving & Sagas

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.

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 textures of the ice caves of Iceland are mesmerising.Photo from Skaftafell Blue Ice Cave Adventure & Glacier Hike

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 glacier?

One of Iceland's many majestic glaciers.

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 ceases to exist and becomes merely a mountain.

They don't call it the land of ice and fire for nothing.

Some glaciers in Iceland have already disappeared completely, such as the former glacier 'Ok'.

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

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.

Northern Lights dancing over Jokusarlon, the Crown Jewel of Iceland.

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.

Glaciers present some truly fantastic opportunities for photography.

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 which 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.' 

Stepping into an ice cave is something of a psychedelic experience.

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?

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.

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.

Ice caves melt each summer, then reform in new and interesting ways each winter.

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. 

Comparing Glacier Caves in Iceland

Some of Iceland's ice caves are enormous! Such is the power of nature...

The most impressive caves in Iceland are the glacier caves. They form naturally when summer meltwater 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.

You've never seen Blue like this!

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. 

Caves such as these are filled with fascinating and complex ice sculptures.

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 of 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.

As the glacier caves are situated in Vatnajökull, that is about a 5-6 hour drive one way from Reykjavík, then a 2-day tour or a 3-day tour of Iceland's South Coast that includes a visit to a glacier ice cave is recommended to have ample time to enjoy all the sights along the way. 

Crystal Cave in Vatnajökull Glacier in Iceland

The ice caves require protective equipment to explore.

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. 

People travel from around the world to visit ice caves 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 the largest glacier ice cave in the area, large enough to fit 70-100 people. 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

Ice caves are considered by locals to be one of the great miracles of nature.

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 many 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.

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 one. 

A naturally formed ice tunnel.

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 many others, has now disappeared and is 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

A river streams through an 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 future.

Northern Lights Ice Cave

You will be equipped with a headlamp and crampons for your time in the 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

Many of Iceland's ice caves are found along the South Coast.Photo from: Katla Ice Cave Tour | Departure From Vík. 

One of the latest ice cave discoveries was made in the glacier of Katla, one of the most dangerous volcanoes in Iceland.

There are actually several glacier caves here, but they are darker than the glacier caves in Vatnajökull glacier and do not contain as much blue ice. The caves are small, with short tunnels in varying colours and if you don't mind getting down on all fours and doing a bit of crawling then you'll be rewarded with some beautiful sights!

On the other hand, this location is more accessible from Reykjavík as the drive to get to the glacier is half of what it is to get to Vatnajökull. Additionally, the Katla ice cave is accessible during summertime!

Katla's ice caves have a darker colour than other ice caves.Photo from: Katla Ice Cave Tour | Departure from Reykjavik. 

Tours going to the glacier cave by Katla started in the winter of 2016-2017, but as the caves stayed safe to enter into the spring and summer months they were also accessible throughout the summer of 2017 and continue to be accessible.

Expect to see black ice when visiting these glacier caves, with small patches of light blue ice, white snow and even some waterfalls with glistening rainbows on sunny days. 

Langjokull Ice Cave

Langjokull has a natural ice cave as well as its Ice Tunnel. Photo from Snowmobile and Ice Cave on Langjokull Glacier from Gullfoss

In Iceland's second-largest glacier, Langjökull, you can both visit a natural glacier ice cave, as well as man-made ice tunnels (which will be detailed a bit further on). The natural ice cave was discovered only recently but is accessible year-round. Its main benefit is that it's not too far away from Reykjavík and can be added onto a thrilling snowmobiling excursion. Additionally, the ride to reach it is an exhilarating one, conducted on a large super truck. 

Glacier Hike & Ice Caving

The ice caves have strange and beautiful openings.Photo from Glacier Hike & Ice Cave Tour from Skaftafell

If you also want to go on a glacier hike, that's a bit more demanding than simply driving up to an ice cave, then sometimes it's possible to hike up to some glacier ice caves, or find your way through massive cracks in the ice. Of course with a qualified guide and all the necessary gear.

This Glacier Hike & Ice Cave Tour from Skaftafell is a 4-hour long trip and is available from mid-October and throughout the month of March. The hike takes you further into the glacier, where you're more likely to come across a glacier cave than closer to the edge of it - meaning that this tour is available a whole 2 weeks before the majority of the glacier ice cave tours start! 

Man-Made Ice Tunnels in Langjökull Glacier

The Langjokull ice tunnel is a manmade Icelandic glacier cave.Photo from Discovering Langjokull Ice Cave Tunnel 

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

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

The ice tunnel is by the peak of Langjokull glacier.Photo from Discovering Langjokull Ice Cave Tunnel 

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 is a beautiful place with a glacier exhibition.Photo by Vidar Nordli-Mathisen

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 located within Perlan, in Reykjavík.

The Glacier and Ice Cave Exhibition is the first of its kind to be opened to the public. It is 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.

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 it's accessible all year round.

If you're looking for something more to do in Iceland's winter wonderland, then check out the Best Winter Activities in Iceland or book a winter package!

Which glacier caves have you visited in Iceland? Are there any cave experiences in particular that you would recommend? Feel free to leave your thoughts and queries in the Facebook comment's box below.