🇮🇸 Iceland · North and east
Lake Mývatn is one of the most astonishing and strangest places in Iceland: a shallow volcanic lake scattered with islets and ringed by a landscape that looks like another planet. Craters, twisted lava fields, columns of steam rising out of the ground, pools of boiling mud and mountains in ochre and sulphur colours make up a setting that sums up, in a few kilometres, all the country's geological fury. We are on the Mid-Atlantic Ridge, the great rift where the American and European plates pull apart and where Iceland is, literally, splitting in two.
The name says it all, though in a difficult language: 'mý' means midge and 'vatn' means lake, so Mývatn means, word for word, 'the lake of the midges'. And it is true: in summer, those clouds of midges (mostly harmless but extremely annoying) are the food that sustains one of the largest concentrations of water birds in the world, with dozens of duck species nesting on its shores. It is a place of extraordinary natural richness, protected as a reserve, as valuable to biology as it is spectacular for the traveller.
This guide covers the best of Mývatn in a practical way: the pseudocraters at Skútustaðir, the lava labyrinths of Dimmuborgir, the great Hverfjall crater, the steaming fumaroles of Hverir, the Grjótagjá cave (famous from Game of Thrones, but where you can no longer bathe), the northern nature baths — the cheaper alternative to the Blue Lagoon — and the Krafla volcanic area, with its geothermal power station and its extraordinary history. We also warn you about what you should know: the summer midges, the strong smell of sulphur and Iceland's very high prices. All in Icelandic krónur, with the equivalent in euros.
Mývatn is a young lake in geological terms: it formed about 2,300 years ago in a great lava eruption that dammed the valley. The whole area is crossed by the Mid-Atlantic Ridge, the fissure where the North American and Eurasian plates pull apart, and that is why it is one of the most volcanically and geothermally active areas in Iceland. Its modern history is marked by two great eruptive episodes: the 'Mývatn Fires' (Mývatnseldar) from 1724 to 1729, and the 'Krafla Fires' (Kröflueldar) from 1975 to 1984, both driven by the Krafla volcanic system. In 1967 a diatomite plant was set up that extracted sediment from the lake bed, which produced a long environmental conflict until it closed in 2004. And in 2009, a borehole of the Iceland Deep Drilling Project accidentally struck a magma chamber at a depth of about 2,100 metres, an extraordinary scientific event. The full geological story, with the pseudocraters, the Fires and the bird reserve, is on our history page.
Read the full history ↓Akureyri, the capital of the north; the volcanism of Lake Mývatn and the Krafla Fires; Húsavík, the whale capital, caught between whale watching and the hunting Iceland still allows; and Seyðisfjörður, the eastern fjord where the telegraph cable that connected the island to the world came ashore in 1906.
Read the history of North and east →No exact prices: a scale from $ (budget) to $$$$$ (luxury), with 2-3 options per category.
Origins, formation and what the sources say.
To understand Lake Mývatn you have to understand that it sits right on top of one of the biggest wounds on the planet: the Mid-Atlantic Ridge, the chain of volcanic fissures where the North American and Eurasian tectonic plates slowly pull apart, by about two centimetres a year. Iceland is one of the very few places in the world where that ridge, normally hidden under thousands of metres of ocean, comes to the surface. The whole country, in fact, is splitting in two along a diagonal band, and the north — with the Mývatn and Krafla area — is one of its most active stretches.
That geological position explains almost everything. Magma rises from the depths through those fissures, and the result is a landscape permanently under construction: recent lava fields, craters, calderas, fumaroles, boiling mud pools and hot water everywhere. The lake itself is young: it formed about 2,300 years ago, when an enormous basaltic lava eruption dammed a valley and created this wide, shallow basin, dotted with islets and pseudocraters. It is not a lake carved by glaciers or rivers, but shaped by fire.
That same activity is what heats the ground and feeds the geothermal springs that make the nature baths possible, what stains the fields of Hverir ochre and sulphur yellow, and what, centuries later, would let Iceland generate electricity from the earth's heat. Mývatn is, in a few square kilometres, an open-air museum of how a volcanic island is born and transformed. Everything the traveller sees — the beautiful and the unsettling — is a direct consequence of living on a rift that never stops opening.
One of the most characteristic and most misunderstood features of Mývatn are its pseudocraters, especially the protected group at Skútustaðir, on the southern shore of the lake. At first glance they look like small volcanoes: they have a rounded cone and a crater at the top. But they are not, and the difference is fundamental. A volcano is an opening through which magma rises from inside the Earth. A pseudocrater, by contrast, has no connection at all with deep magma: it is, literally, a 'false crater'.
They form through steam explosions. When a very hot lava flow advances over waterlogged ground — a marsh, a lake shore, water-saturated soil — the water trapped under the lava heats suddenly to boiling and turns to steam. That steam, sealed in and under rising pressure, eventually bursts upwards through the still-soft lava, throwing out fragments that pile up around the point of the explosion. Repeated many times, the process builds these cones with craters that mimic real volcanoes but are in fact 'scars' from a battle between lava and water. That is why they are also called rootless craters: they have no root going down to the magma.
Mývatn's pseudocraters are among the most famous and most studied examples of this phenomenon in the world, to the point that geologists use similar formations found on Mars to work out where there was water on the red planet. There are several groups around the lake, but the one at Skútustaðir, with its paths between ponds, is the most visited and accessible. Understanding that they are not volcanoes completely changes how you read the landscape: Mývatn is as much the story of water as of fire, and of what happens when the two suddenly meet.
The modern history of Mývatn is written by two great eruptive episodes of the Krafla volcanic system, two and a half centuries apart but surprisingly similar to each other. The first were the so-called Mývatn Fires (Mývatnseldar), which ran from 1724 to 1729. They began spectacularly in 1724 with the explosive formation of the Víti crater ('hell'), and continued with the opening of numerous fissures and lava flows in the following years, which threatened farms and even the church at Reykjahlíð. Local tradition tells that the lava surrounded the church but stopped just short of destroying it, an episode etched into the community's memory. Those fires, in an age without modern science, were lived through with religious terror.
The second episode, the Krafla Fires (Kröflueldar), took place between 1975 and 1984 and was observed, this time, with all the instruments of contemporary geology. Over those nine years, the Krafla caldera staged a long sequence of events: the ground swelled and sank again and again as magma built up and drained through the underground fissures, in some fifteen cycles of inflation and deflation, accompanied by nine eruptions that opened new cracks and spilled fresh lava over the landscape. Scientists consider the Krafla Fires to have been, in essence, a continuation of the same mechanism that had produced the Mývatn Fires in the eighteenth century: the same volcanic system, behaving almost identically.
These eruptions are not a fact from the distant past: the black lava of Leirhnjúkur, which travellers can walk over today beside the lake, still steams in places and is only a few decades old. Walking on it means treading the youngest ground in Iceland. And Krafla is still an active, monitored volcano, capable of waking again. Mývatn is not a finished landscape but a work in progress.
Mývatn's volcanic wealth also made the lake a target for economic exploitation, with controversial consequences. In 1967 a diatomite (kieselguhr) plant was set up at Bjarnarflag, beside the lake: a material formed from the microscopic shells of diatoms, algae that accumulate on the bed of Mývatn. The plant pumped that sediment from the lake bed and dried it using geothermal steam, to produce a powder used as an industrial filter and abrasive. For decades it was a source of local jobs, but it was also the cause of an intense environmental conflict: dredging the lake bed disturbed its delicate ecosystem, on which the famous water birds depend. Pressure from scientists and environmentalists, together with economic factors, led to extraction closing in 2004. The episode is an early example of the Icelandic tension between exploiting natural resources and protecting unique landscapes.
One of the most extraordinary scientific events in the history of geothermal energy worldwide also happened in that same area. In 2008-2009, the Iceland Deep Drilling Project (IDDP) drilled a borehole at Krafla, IDDP-1, with the ambition of reaching 'supercritical' geothermal fluid at a depth of about 4,500 metres, far hotter and more energetic than the usual kind. But at barely 2,100 metres the drilling ran into something unexpected and, in principle, dreaded: fresh volcanic glass in the samples showed the bit had gone straight into a magma chamber. Drilling into magma is, for geothermal engineers, just about the only thing they are taught to avoid.
Instead of abandoning the well, the team decided to study it and put it into production. IDDP-1 turned out to be one of the most powerful geothermal wells ever measured, capable of generating an enormous amount of energy from the heat close to the magma, and it opened a pioneering line of research into how to harness that extreme source directly. All this, a few kilometres from where ducks nest among the pseudocraters. That is Mývatn: a place where the most fragile biology and the most brutal geology live minutes apart.
Behind its volcanic landscape, Mývatn hides one of Iceland's greatest biological riches, and it all starts with its name: 'mý' means midge and 'vatn' lake. Mývatn is, literally, 'the lake of the midges'. Far from being a flaw, those enormous clouds of midges that appear in summer are the base of the whole ecosystem. The larvae of those insects live by the million on the shallow, nutrient-rich lake bed, and their abundance supports an exceptional food chain. That is why Mývatn and the Laxá river that flows out of it hold one of the richest populations of breeding water birds in the world: more than a hundred bird species have been recorded in the area, with more than a dozen duck species nesting on its shores.
Among those birds there are real rarities for European birdwatchers. Mývatn is the only place in Europe where the spectacled long-tailed duck, the Icelandic pochard or 'Barrow's goldeneye' breeds, a duck with a golden eye and a characteristic white patch that lives here all year. It is also a refuge for the harlequin duck, with its blue, chestnut and white plumage, which favours the fast water of the Laxá. That biological value led to the area being protected: the lake and its surroundings have been a special nature reserve since 1974, with strict rules to preserve the habitat, and Mývatn and Laxá together are among the sites Iceland puts forward for their international ecological importance.
Today, that double nature — geological and biological — is what draws travellers. Mývatn is at once a laboratory of living volcanism and a bird sanctuary; a place where in a single day you can walk among steaming lava, look into a crater, bake bread underground, bathe in geothermal water and watch very rare ducks among the pseudocraters. A reserve for half a century, it remains a delicate balance between tourist and energy use and the conservation of a unique ecosystem, born, like everything here, of the rift that splits the island in two.