Hverfjall

What makes it special

Hverfjall is a tephra ring, a crater built of loose ash rather than lava. It formed in one short, violent eruption a little over 2,500 years ago, when magma rising under the Mývatn area met water and blew apart into fine fragments. That ash is what crunches and slides under your boots on the way up.

The ash settled evenly around one central vent, so the rim forms a single unbroken circle about a kilometre across.

The bowl inside drops about 140 metres, and it is bare and dark, with no trees and no large plants. From the rim you look straight down into it, and the scale is far bigger than it seems from the road.

Look back as you climb, too. The lake comes into view halfway up the outer slope, well before the top.

Visiting

Hverfjall's main car park, on the northwest side, has toilets and a small information stand, so start there. From it the path climbs steeply over loose ash, and most walkers reach the rim in about 20 minutes.

The south path starts from the opposite side of the crater and climbs a slightly gentler slope. Choose it if the steep start worries you.

Once on top, a mostly level path circles the whole rim, and you can walk the full circle at your own pace. Outside the busiest hours you may share it with only a few other walkers.

Guided or on your own

You do not need a guide: the paths are marked and the loop is easy to follow on your own. If you have no car, several tour companies in the area run guided trips that take in Hverfjall with other stops nearby.

Tips

Bring a windproof jacket, a hat and water, because the rim is exposed and the wind on top is often strong. Trainers are enough on a dry day, and a few walkers carry poles.

On the way down, take short, careful steps, because the slope is loose volcanic ash. Keep to the marked paths, which protect the slopes from erosion.