Askja Caldera and Askja Víti, Iceland

Askja Caldera is a subsidence caldera in the Highlands region of Iceland. Formed 10 thousand years ago, more recent eruptions have changed the landscape and allowed a stunning lake and smaller explosion crater to form. The smaller crater known as Askja Víti has a small lake which is geothermally heated and perfect for swimming in the right conditions.

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Exploring Askja Caldera

Leaving the parking space at Vikraborgir behind the path through the lava field heads up hill to the lip of the caldera. A small incline with sharp chaotic lava abutting hills is coated in the remains of the winter snow. As the caldera comes into view the sheer scale of the area hits hard.

In the distance the Dyngjufjöll Mountains can be seen on the northern side of the UNESCO Vatnajökull National Park. Rising to over 1000 metres they are an impressive sight. A path meanders across the caldera. More of a worn trail than a path, indistinct in places but the intermittent markers show the way whatever the conditions.

Askja is a 45km² subsidence caldera formed when the roof to a magma chamber collapsed after an eruption about 10 thousand years ago. Later small eruptions filled the caldera with ash and lava until a large eruption in 1875 threw pumice and ash into the caldera and the surrounding area. Again the magma chamber roof collapsed and a new caldera formed. Over the next 30 years the caldera filled with ground water and the stunning 11km² Öskjuvatn Lake was formed. This is the deepest lake in Iceland with a depth of 217m. At the same time the smaller Víti explosion crater formed adjacent to Öskjuvatn Lake

Askja Víti

During the eruption in 1875 pumice was thrown from the crater and towards the end of the eruption a small eruption crater Víti was formed. This deep crater is located on the northeast shore of Öskjuvatn a water filled caldera formed during the same eruption.

Víti means ‘hell’ in Icelandic and this vivid blue geothermal lake with boiling vents around its edge may well be the entrance. After walking across the barren lava fields Öskjuvatn comes into view before the hidden Víti crater is seen.

The path to the shore is steep following a river bed which even in good weather is slippery and difficult, but the rewards are worth the effort.

The water is pungent and murky. Bubbles rise to the surface as pockets of gas are disturbed, the smell of sulphur clinging to your hair, skin and clothes as a reminder of your visit for days. Despite the smell the water is an inviting temperature. Perfectly heated by the volcanic rumblings just below the surface.

The shoreline is coated in crystals. All colours of the rainbow from deep blue to vivid orange. A chemistry lesson surrounds you as you stroll the short distance from the path into the crater to the small waterfall.

This may be one of the most beautiful and unique places to swim in Iceland.


Safety at Víti Crater

Before visiting the crater you really should speak to the rangers at Drekki. They will advise you on whether it is safe to walk out to the crater and what the water conditions are like. The walk takes 45 minutes each way and the weather can change in a moment. The rangers will be able to give advice and local knowledge.

The path out to the crater is marked but in poor visibility it would be easy to wander off the path, if visibility does drop return rather than continue in the hope of not getting lost.

Walking down into the crater is very steep. In dry weather it is difficult but in wet weather whilst you may get down into the crater coming back up would be impossible. If the rangers have put signs saying you should not go down into the crater then do as you are told!

Within the crater on the shore line there is a clearly marked geothermal area. It is difficult to miss as it is boiling away. There are signs incase there is any doubt about the boiling steam that it is constantly emitting. To the right of the path down there is a small rope barrier. Stay to the left of this as there are constant rock falls from the crater walls.

Photography Notes

Askja is one of the most beautiful landscapes in Iceland. Despite being flat the caldera walls and the Dyngjufjöll Mountains give perspective to the area. The colours of the lava change as you progress across the caldera and snow clings in places even in the middle of summer. As you walk across the caldera look at the craters and rocks that pepper the walls. They each have a unique appearance and vary in size, shape and colour.

Including people in your photographs will give a true sense of the scale. In summer this is harder as they blend with the colours of the landscape, but in the winter when there is snow on the ground, walkers add a new dimension to your photography.

On the edge of the caldera the lava is black and red. A great contrast and there is every size from tiny pieces of gravel to large rugged boulders. Take your time to explore what at first appears to be just a jumble of rocks. Shapes and colours will emerge the longer you look.

Öskjuvatn Lake on a good day will reflect the mountains behind. The best view of the lake is from the rim of the Víti explosion crater. This will provide height and a clear view. The only way to include the whole lake and mountains is with a panorama, it really is vast.

In the winter months the whole area is covered in a blanket of snow. It is easy to become disorientated with such a vast flat landscape. However the contrast of lava against snow and the frozen lake make for stunning and perfect images.

Víti crater can be photographed at any time of the day and in most safe weather conditions. From the rim of the crater it is possible to include Öskjuvatn behind within the photograph with the use of a wide lens.

Once inside the crater it is best to focus on the details. There are so many colours and patterns that it really is impossible to not find a unique perspective.

Hiking Askja Caldera

Distance: 5km plus exploring crater
Minimum time: 2 hours plus swimming time
Ascent: 48m
Start and Finish: Vikraborgir Car Park
Road: F894
Parking: 65.06912°N, 16.71144°W
Nearest Town: No towns within 4 hours drive

There are clear trails and you can reach the caldera from the car park or by a longer walking route from Dreki. The rangers in Dreki can advise on routes and weather conditions.

When you reach the parking area there is a map with information about the routes and times, although these are just estimates. The walk across the caldera is clearly marked with yellow markers which you should follow whatever the weather and ground conditions. the path is indistinct and it is easy to wander off.

If you want to find out more or have company then there are daily guided walks across the caldera leaving from the car park.


Getting to Askja

Askja is not any easy place to reach. It is reached by driving across lava fields and ash from Ring Road 1 following either the F910 or F905 to Dreki and then continuing along the F894 to the Vikraborgir car park at the end of the road. Whichever route is taken at least four hours if not more is needed after leaving the ring road to get to Askja. A 4WD vehicle is essential as the road is rough and there are a number of river crossings to ford.

Have a look at car hire options and book..

The road is not open all year round and conditions change rapidly so the local conditions should be checked. It is also best to check with the rangers at Dreki before continuing to Askja.


Given the terrain and potential weather conditions, a tour of the Highlands is the easiest and safest way to visit this area of Iceland. There are a huge range of tours, from super-jeep to threking and camping with a guide. It really is down to your fitness level, what you want to see and the amount of time you have available to the exact tour that you choose. They will all give an amazing experience to this volatile but remote corner of the country.

Browse the tours of the Highlands and book here..

Other Places Nearby

  • Dreki – base for the mountain rangers at Askja with mountain huts
  • Nautagil – a deep gorge used to train NASA scientists
  • Stuðlagil Canyon- a gorge with large basalt columns

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