Jökulsárgljúfur

In the north-east of Iceland, the grey, silt-laden glacial river Jökulsá á Fjöllum drops off the edge of a barren lava plateau and spends the last stretch of its journey to the Arctic Ocean inside a canyon of its own making. Jökulsárgljúfur, "the canyon of the glacier river", runs for about 25 km from south to north, often half a kilometre wide and in many places more than 100 metres deep. Along its length the river thunders over a chain of waterfalls, beginning with Selfoss and Dettifoss, the latter a 44-metre curtain of muddy water often described as the most powerful waterfall in Europe, followed by Hafragilsfoss and smaller falls and rapids further downstream.

The canyon is young by geological standards. Between about nine and eight thousand years ago, volcanic fissures nearby poured out thick sheets of lava. After the last Ice Age, as the great Vatnajökull ice cap far to the south retreated, sudden glacial outburst floods released by eruptions beneath the ice surged down the river with enormous force, cutting through the lava layers in a matter of days rather than millennia. The floods left behind a gallery of strange forms. At Hljóðaklettar, the "echo rocks", the eroded cores of old volcanic vents stand in clusters of twisted basalt columns that radiate in rosettes and fans, while at Rauðhólar a red scoria cone has been sliced open by the river. The canyon walls themselves expose layer upon layer of lava, stained in shades of black, rust and ochre.

At the northern end lies Ásbyrgi, a horseshoe-shaped gorge with sheer walls up to around 100 metres high, enclosing a quiet birch woodland and a small pond. Geologists see it as a dry former channel of the same river, carved by catastrophic floods; local tradition holds that it is the hoofprint of Sleipnir, the eight-legged horse of the god Odin, pressed into the earth as he galloped across the sky. Jökulsárgljúfur was protected as a national park in 1973, and Ásbyrgi was added to it a few years later. Since 2008 both have formed the northern part of Vatnajökull National Park, one of the largest protected areas in Europe.

Getting there

The canyon lies in north-east Iceland, between Lake Mývatn and the bay of Öxarfjörður. Roads run along both rims, Route 862 on the west and Route 864 on the east, linking the Ring Road in the south with Ásbyrgi in the north. The nearest town is Húsavík, about 40 km to the west, and the largest town in the north, Akureyri, is about 76 km away in a straight line. Akureyri Airport (AEY) is about 77 km away, and the small airport at Húsavík (HZK) is closer still. Iceland has no railways; the canyon is reached by road.