Askja

Askja is not a single mountain but a nest of collapsed craters set inside the Dyngjufjöll range, a cluster of peaks in the empty interior of northeast Iceland that tops out around 1,500 metres. The volcano sits in the rain shadow of Vatnajökull, the great ice cap to the south, so the land around it is one of the driest in the country: black pumice, lava fields and bare gravel that stretch to the horizon with almost nothing growing on them. The central volcano is some 20 kilometres across, and a fissure swarm running north from beneath the glacier for nearly 190 kilometres feeds it. Geologists count well over a hundred eruptions from this system in the last seven thousand years.

What draws the eye is a set of calderas nested one inside another. The oldest and widest is a basin of about 50 square kilometres left by a prehistoric eruption; within it lies the main caldera, roughly eight kilometres wide. Then, in March 1875, a violent eruption lasting about seventeen hours threw out close to two cubic kilometres of tephra, and over the following months the ground sank to form a new hollow about five kilometres across. Water filled it, and the result is Öskjuvatn, a deep-blue lake roughly 220 metres deep, the second deepest in Iceland, lying some 50 metres below the floor of the surrounding caldera and frozen for much of the year. Ash from 1875 fell as far away as Scandinavia and Germany, and in the east of Iceland the fallout smothered pasture so badly that at least sixteen farms were abandoned the following year.

Beside the lake is Víti, a small explosion crater from the same eruption, whose steep sides cradle a pool of milky, sulphur-scented geothermal water. Bathing there is a long-standing tradition, though the path down is steep and slippery. The place also holds two well-known stories. In 1907 the German geologist Walter von Knebel and the painter Max Rudloff rowed out on Öskjuvatn in a canvas boat and were never seen again; von Knebel's fiancée, Ina von Grumbkow, came to Iceland the next year to search for them. And in the 1960s NASA brought Apollo astronauts to the lava fields here to practise field geology before the Moon landings, an episode remembered by a monument in Húsavík listing their names. The last eruption, in late 1961, left the dark Vikrahraun lava flow on the caldera floor, and since 2021 the ground has been measurably rising again.

Getting there

Akureyri, Iceland's largest northern town, is about 96 kilometres away in a straight line, and Akureyri Airport (AEY), with domestic flights from Reykjavík, is about 93 kilometres away. By road the volcano is far more remote: the approach is roughly 100 kilometres of highland F-road from the Ring Road to the Dreki hut, then about 8 kilometres further up into the caldera, followed by a walk of around 2.5 kilometres across the pumice to Víti and the lake shore. The highland roads normally open only from late June to early October and involve river fords, so most visitors come on a super-jeep or bus excursion from the Mývatn area; there are mountain huts and a campsite at Dreki.