Dettifoss, Iceland: Europe’s Most Powerful Waterfall

Dettifoss announces itself long before the canyon comes into view. A low roar carries across the stony plateau of north-east Iceland, a column of spray rises above the rim, and then the ground falls away to reveal a wall of grey glacial water about 100 metres wide, dropping some 44 to 45 metres into the gorge of Jökulsárgljúfur. It is often called the most powerful waterfall in Europe, a title that depends a little on how you measure it, and it is certainly one of the great sights of the island. This guide explains where Dettifoss comes from, how floods of almost unimaginable size shaped its canyon, what the walk to the falls involves, and the road on from here across the highland desert of Möðrudalsöræfi. On Day 11 of our Iceland cultural and wilderness small group tour, the group makes a detour to Dettifoss on the drive from Lake Mývatn to Egilsstaðir.

Where Dettifoss is and the river that feeds it

Dettifoss lies on the Jökulsá á Fjöllum, the “glacial river in the mountains”, which rises from the northern edge of Vatnajökull, Iceland’s largest ice cap, and runs north for about 206 kilometres to the sea at Öxarfjörður. It is Iceland’s second-longest river, and because it drains a vast area of ice and volcanic upland, it carries a heavy load of fine sediment. That is why the water at Dettifoss is not white or blue but an opaque grey-brown, the colour of wet concrete, and why the spray leaves a fine grit on spectacles and camera lenses.

The falls sit within the Jökulsárgljúfur section of Vatnajökull National Park. Jökulsárgljúfur was declared a national park in its own right in 1973 and became part of the larger Vatnajökull National Park in 2008. The canyon it protects runs for about 25 kilometres below the falls and is in many places more than 100 metres deep. Dettifoss is one of a chain of waterfalls in this stretch of river: Selfoss, a broad, ragged step about 10 metres high, lies only a few hundred metres upstream, while Hafragilsfoss and Réttarfoss lie further downstream in the canyon.

Weighing the “most powerful” claim

Dettifoss is widely described as Europe’s most powerful waterfall. Vatnajökull National Park uses the phrase, as do the regional tourism offices for North Iceland, and the park suggests a simple test: put your palms against the rock near the falls and feel it vibrate. The figures behind the claim are a drop of about 44 to 45 metres and a width of about 100 metres, with an average flow that sources put at around 190 to 200 cubic metres a second. Flow rises sharply in the summer melt, and some regional sources quote figures of up to about 500 cubic metres a second.

The claim is not uncontested. Power in a waterfall is usually understood as the volume of water multiplied by the height it falls, and here the Rhine Falls in Switzerland is the obvious rival. It drops only about 23 metres, roughly half the height of Dettifoss, but Zurich Tourism gives its summer flow as 600 cubic metres a second, and Swiss sources describe it as Europe’s largest waterfall. Depending on the season and the figures used, either can be argued to deliver more raw power. What can be said with confidence is that Dettifoss combines great volume with a single, sheer drop in a way few falls in Europe can match, and that on a summer day it is hard to imagine anything more forceful.

A canyon carved by floods

For a long time the canyon of Jökulsárgljúfur was assumed to be the work of steady erosion over thousands of years. Research led by geoscientists at the University of Edinburgh, published in the Proceedings of the National Academy of Sciences, told a more dramatic story. The study found that much of the canyon was cut in a few extreme floods, roughly 9,000, 5,000 and 2,000 years ago. Volcanic eruptions beneath Vatnajökull melted the ice and released glacial outburst floods, known in Icelandic as jökulhlaup, which tore up the basalt bedrock and pushed Dettifoss and its neighbouring falls upstream by as much as two kilometres at a time.

The national park describes the same process in its own terms: the canyon was shaped by the river over thousands of years, helped by catastrophic floods from Vatnajökull, the most recent major floods occurring around 2,000 years ago. Erosion has not stopped. The park notes that Dettifoss is still cutting back into its lip and moving south, upstream, by around half a metre a year. Standing on the rim, it is worth remembering that the gorge at your feet may owe more to a few days of catastrophe than to the patient work of millennia.

Which side of Dettifoss is better, east or west?

Both banks are worth seeing, and the main difference is the road and the angle of view rather than the falls themselves. The west bank is reached by road 862, which is paved from the Ring Road, while the east bank is reached by road 864, a slower gravel road. Vatnajökull National Park notes that the spray drifts towards the west bank, so that side is usually the wetter one, and Visit Akureyri reports that newer viewing platforms on the west side give access to a larger part of the falls. The east bank has a simpler, more rugged approach and a different perspective across the face of the water.

The tour itinerary describes Dettifoss as a detour on the drive from Mývatn to Egilsstaðir and does not specify which bank the group visits. Both side roads leave the Ring Road on either side of the Jökulsá á Fjöllum, so either fits the route. If the viewpoint matters to you, a Tour Specialist can talk you through what to expect.

How much walking is involved at Dettifoss?

Expect a short but rough walk of about 1.5 kilometres there and back on the west side, which the national park rates as easy and suggests allowing half an hour to an hour for. The path crosses uneven basalt and gravel, with some rough steps, and near the falls the spray can soak the ground and make it slippery, so sturdy walking shoes with a good grip and a waterproof jacket are essential. For those with more time and energy, the park also marks a 2.5-kilometre loop from the west car park that continues upstream to Selfoss and back, taking about an hour.

There are no trees and little shelter on this plateau, and the wind can be cold even in summer. Paths at Iceland’s waterfalls are sometimes closed for safety or repairs, and the national park asks visitors to keep to marked trails and stay back from the canyon edge. At the time of writing, it is wise to check trail notices with Vatnajökull National Park before you go.

Is Dettifoss worth the detour?

Yes: for most travellers Dettifoss is the most physically overwhelming sight on the northern half of the Ring Road. It lacks the delicate setting of some of the south-coast waterfalls, but that is the point. Here the scale and noise of a glacial river in full flow are laid bare in a raw, almost lunar landscape, and the sense of geological force is more vivid than at any museum. The detour from the main road adds some time to the day, but few who make it regret it.

Can you visit Dettifoss in winter?

It is possible, but winter access is limited and unpredictable. At the time of writing, regional tourism sources say the paved road 862 on the west side has only limited winter service and can close at short notice, while the gravel road 864 on the east side has no winter service and usually does not reopen until early summer. Near the falls, the national park warns that large drifts of snow and ice can build up in hard frost, and advises visitors not to go right to the canyon edge. If you are travelling independently outside the summer months, check road conditions on umferdin.is, travel warnings on safetravel.is and the forecast from the Icelandic Met Office at vedur.is before you set out.

The road across the highland desert of Möðrudalsöræfi

From Dettifoss the journey to the east crosses one of the emptiest stretches of the Ring Road. Möðrudalsöræfi, the wilderness of Möðrudalur, is a high plateau of gravel, pumice and sand, sparsely tufted with grass and moss and laced with old lava. It is often described as a highland desert, and the description fits: in places there is little to see but the road, the sky and the outlines of distant mountains. On a clear day the flat-topped table mountain of Herðubreið, about 1,682 metres high and often called the queen of Icelandic mountains, rises from the plateau to the south. It formed as a volcano erupting beneath the ice of the last glaciation, which is why its sides are so steep and its summit so level.

The farm of Möðrudalur, a short way off the main road, sits at about 469 metres above sea level and is described by East Iceland’s tourism office as the highest settled farm in Iceland. Its small church, built in 1949 by the farmer Jón A. Stefánsson in memory of his wife, is a reminder that people have long made a living even on this hard ground. Weather on the plateau can change quickly, and in winter storms can close the road altogether.

Dettifoss on Day 11 of the tour

Dettifoss comes at a natural turning point in the circuit of the island. On Day 9 the group visits Godafoss and spends the rest of the day around Lake Mývatn, among pseudo-craters, the lava formations of Dimmuborgir and the mud pools at Námaskarð; our guide to the volcanoes, craters and birdlife of Lake Mývatn covers the area in depth. Day 10 begins with a boat trip from Húsavík to look for whales, described in our article on whale watching from Húsavík, and the afternoon is spent in the northern part of Jökulsárgljúfur at the horseshoe canyon of Ásbyrgi and the echoing rocks of Hljóðaklettar. By the time the group reaches Dettifoss, it has already seen the far, gentler end of the same canyon.

On Day 11 the group leaves Mývatn and crosses the highland desert of Möðrudalsöræfi to Egilsstaðir, taking the detour to Dettifoss on the way. After arriving in Egilsstaðir, the group explores Lake Lögurinn, which saga tradition says is home to a monster, drives through Hallormsstaðaskógur, the largest forest in Iceland, and views the waterfall of Hengifoss before the day ends back in Egilsstaðir. Our guide to Egilsstaðir and East Iceland describes the town and its surroundings, and our 17-day Ring Road itinerary for mature travellers shows how this leg fits into the whole journey.

The tour is rated Level 2, Moderate: participants need to be able to carry their own luggage, climb and descend stairs, and take part in three to five hours of physical activity a day, the equivalent of walking or hiking up to 8 kilometres on uneven ground. An Odyssey Program Leader travels with the group throughout.

Dettifoss is best understood as the visible edge of a much larger story: a river born under Iceland’s largest ice cap, floods that remade the land in days, and a waterfall that is still eating its way upstream. On the Iceland cultural and wilderness tour, a small group of up to 16 travellers stands at its rim with an Odyssey Program Leader before heading on across the highland desert to the quieter landscapes of the east.