Lake Mývatn: Volcanoes, Craters, Birds and the Making of North Iceland

Few places on the tour compress so much of Iceland’s volcanic story into a single afternoon as the basin around Lake Mývatn. Within a few kilometres you can stand on a lava field that was still erupting within living memory, walk between grass-topped pseudo-craters formed the moment lava met water, and watch steam rise from ground that has been quietly cooking since the last Ice Age. Odyssey’s Iceland cultural and wilderness small group tour spends a full day here on its ninth day, and the lake rewards that time: it is not one attraction but five, each telling a different part of how North Iceland was made.

A lake with five kinds of volcanic evidence

Lake Mývatn sits in an active volcanic zone in North Iceland, and the ground around it has behaved differently every few hundred metres for thousands of years. On the tour’s wider circumnavigation of the island, this is the day the itinerary slows right down — rather than moving between towns, the group spends the day working through one basin site by site: the pseudo-craters at Skútustaðir, the lava sculptures at Dimmuborgir, the geothermal ground at Námafjall, the explosion crater Viti, and the 1970s lava field at Leirhnjúkur. Each is a different kind of volcanic event, and seeing them in sequence, on foot, does more to explain Icelandic geology than any single formation could on its own.

The pseudo-craters at Skútustaðir

The rounded, grass-covered mounds at Skútustaðir look like small volcanoes, and in outline they are — but they never had a magma chamber of their own. Pseudo-craters form when hot lava flows out across a wet lake bed or marsh; the water beneath the flow boils, and the trapped steam blasts upward through the cooling lava, throwing debris into a ring around the vent as it escapes. The result is a genuine crater shape built entirely by steam, not eruption. Dozens of them cluster around the lake’s southern shore, and a gravel path loops between the largest, giving a close view of the crater rims without leaving the marked track.

How much walking does a visit to Lake Mývatn involve?

Across the whole tour, Odyssey rates the activity level as Level 2 – Moderate, meaning travellers should be comfortable with three to five hours of walking a day, at times on uneven ground, up to around eight kilometres. A day at Mývatn sits within that range: the paths at Skútustaðir and the geothermal ground at Námafjall are unpaved and occasionally loose underfoot, and there are short, gentle inclines rather than sustained climbs.

Dimmuborgir: lava sculptures with a story attached

A short drive from Skútustaðir, the lava field at Dimmuborgir — the “Dark Castles” — is one of Iceland’s stranger landscapes: a maze of tall, twisted basalt columns and hollow lava tubes formed roughly 2,300 years ago, when a lava lake drained away and left its crust standing in broken pillars. Icelandic folklore places the entrance to the underworld here, and the shapes do the imagery no favours — there are archways, spires and what look, at a distance, like ruined towers. Marked walking loops of varying length run through the formation, so travellers can go as far into the maze as they’re comfortable with before rejoining the group.

Geothermal ground at Námafjall and Hverir

Cross the ridge east of the lake and the landscape changes completely. At Námafjall, and the geothermal field known locally as Hverir, the ground itself is at work: mud pots bubble in ochre and grey, fumaroles hiss jets of steam, and the earth is stained yellow and orange with sulphur deposits. Boardwalks keep visitors on stable ground and away from the hottest vents, but the smell reaches well beyond the walkways.

Why does the Mývatn area smell of sulphur?

The smell is hydrogen sulphide gas, released as groundwater is heated by magma close to the surface and forced back up through cracks in the rock. It’s the same geothermal system that heats homes and greenhouses elsewhere in Iceland, but at Námafjall it reaches the surface raw, without being piped anywhere first. The smell is strongest right at the mud pots and fades quickly once you’re back on the coach.

Viti and Leirhnjúkur: two eruptions, two centuries apart

Two further stops round out the geological picture. Viti — the name means “Hell” — is a wide explosion crater dating to the Myvatn Fires of 1724 to 1729, now holding a pale, mineral-blue lake. A short walk further on, Leirhnjúkur is younger again: its black lava field erupted in a series of events between 1975 and 1984, and in places the surface still shows the cracked, glassy texture of lava that solidified within living memory of some of the tour’s own guides. Walking between the two sites — one crater nearly three hundred years old, one lava field barely fifty — is as close as most travellers will come to feeling the timescale of an active volcanic zone.

Why the lake itself matters

It’s easy, surrounded by so much volcanic drama, to overlook the lake Mývatn is named for. Mývatn means “midge lake”, and the insect life the name refers to is exactly why the lake supports one of the richest concentrations of breeding ducks anywhere in the world — more than a dozen species nest here each summer, drawn by the shallow, nutrient-rich water the volcanic basin has created. Sigurgeir’s Bird Museum, on the lake’s northern shore, holds Iceland’s largest private bird collection and sets the wildlife in context before the group moves on.

Is a visit to Sigurgeir’s Bird Museum included in the tour?

Yes. The museum visit is part of the standard day-nine itinerary, alongside the pseudo-craters, Dimmuborgir, Námafjall, Viti and Leirhnjúkur, with two nights at a hotel in the Mývatn area either side of the day’s exploring.

How Lake Mývatn fits the wider route

The tour reaches Mývatn partway through its 17-day circumnavigation of Iceland, arriving from the north coast and moving on the following day to a whale-watching day trip to Húsavík and the canyon country of Jökulsárgljúfur National Park. Coming the other way, earlier stops on the route take in the seal colonies of the Vatnsnes Peninsula. The geothermal ground at Námafjall is also a useful preview of a theme the tour returns to further south, where Icelanders put the same volcanic heat to work warming homes and greenhouses rather than leaving it to vent at the surface.

Planning your visit

Mývatn’s isolation is part of what makes it work as a full day rather than a quick stop — there’s enough here, spread across a wide enough area, that trying to see it independently in a single afternoon usually means choosing between the geology and the birdlife. On the escorted tour, a local guide sets the pace between sites and explains what you’re looking at as you go, which matters more here than almost anywhere else on the route.

Is there a single supplement for solo travellers on this tour?

Yes, a single supplement applies for solo travellers on the Iceland cultural and wilderness small group tour, as it does across Odyssey’s small group tours. Solo travellers join the same group, itinerary and guiding as couples throughout, including at Lake Mývatn.

When does the tour visit Lake Mývatn, and might we see the Northern Lights?

The tour departs in April and September. Northern Lights sightings depend on clear skies and solar activity and can’t be guaranteed on any departure, but Odyssey notes them as a realistic possibility on the September circuit, when nights are dark enough for the aurora to be visible if conditions align.

Lake Mývatn is, in the end, a working demonstration of the forces that shaped this part of Iceland — steam-built craters, folklore-laden lava, raw geothermal ground and an eruption young enough to remember, all within walking distance of a lake dense with birdlife. It’s the kind of day that rewards having a guide beside you rather than a map, which is exactly what the small group format is built for.