Kerlingarfjöll sits roughly in the middle of Iceland, far enough from the coast that the air feels different, thinner and quieter, and the landscape drops most of its familiar green. What you get instead is a dense cluster of rhyolite peaks stained rust, ochre, and sulfur yellow, cut through by steaming vents and warm streams. It is one of the few places in the Icelandic highlands where volcanic heat and dramatic color converge at a scale you can actually walk through.

Why It’s Worth the Trip

Most highland destinations reward you with a single feature: a glacier tongue, a lava field, a waterfall. Kerlingarfjöll rewards you with sustained layering. The rhyolite produces colors that shift with the light, moving from burnt orange in flat overcast to something closer to deep red when the sun catches the hillsides at an angle. The geothermal activity is not confined to a single vent or pool but spread across the Hveradalir valley, where fumaroles push steam through the ground at multiple points and the soil stays warm underfoot. Warm streams cut through the terrain, and the contrast between hot, mineral-stained ground and snowfields that persist well into summer gives the whole area a compositional strangeness that photographs tend to flatten.

The hiking here is genuine highland hiking, meaning the trails are marked but not manicured, the terrain shifts between loose volcanic scree and stable packed earth, and the elevation changes are real. A full circuit of the Hveradalir area will take most walkers four to six hours depending on pace and how much time is spent around the geothermal features. There are also longer routes that connect different parts of the massif, making it possible to spend two or three days here if you have the equipment and the time.

This is not a roadside stop. The geothermal valley requires a walk in, and reaching the more dramatic terrain means gaining and losing elevation on uneven ground. The payoff is genuine, but the effort should be factored in from the start.

How to Get There

The primary route in is via the F35, commonly called the Kjölur road, which runs through the central highlands between the Langjökull and Hofsjökull glaciers. Kerlingarfjöll lies east of F35 on an interior road designated F347. Both roads require a four-wheel-drive vehicle with high clearance. This is not a recommendation to test an ordinary rental car on an F-road. River crossings and soft ground are part of the route, and conditions change depending on recent weather and the season.

The F35 is generally one of the more accessible highland routes, often opening earlier in summer than roads on the south and east sides of the interior, but “accessible” here is relative. Check road conditions through the Icelandic Road and Coastal Administration before departure. Road status in the highlands changes with little warning.

There is a staffed mountain hut and campsite at Kerlingarfjöll run by the Touring Club of Iceland (Ferðafélag Íslands), which provides a base for hikers and some basic services during the summer season. Staying there makes a full exploration of the area considerably more practical than attempting it as a single very long day trip from the Ring Road.

What to Expect on Arrival

The approach through F347 gives you your first views of the massif from a distance, and the color differentiation is visible even before you park. The peaks themselves are modest in absolute height compared to Iceland’s larger volcanic systems, but the density of features packed into a relatively compact area makes the landscape feel full.

The main hiking focus is Hveradalir, the geothermal valley. Trails lead from the hut and campsite area into the valley, and the route involves crossing terrain that mixes solid ground with patches where the earth is warmer than expected, the soil looser, and the colors more acidic. The fumaroles in Hveradalir produce steady columns of steam that drift depending on wind direction. When the wind is calm the steam rises vertically and the smell of sulfur is noticeable but not oppressive. In windier conditions the steam disperses quickly.

The warm streams in the valley floor are shallow and clear over the colored mineral deposits. Some sections of trail run directly alongside them. Snow lingers in the high hollows and shadowed gullies into late summer, and the contrast with the warm, steaming ground nearby is one of the genuinely unusual visual qualities of the place.

Summit routes exist for those who want extended elevation, and on clear days the views across the central plateau extend to both Langjökull and Hofsjökull. Clear days in the highlands are not guaranteed. Cloud and mist arrive quickly and can reduce visibility to a short distance with little advance notice.

When to Go

Kerlingarfjöll is a summer destination, with the practical window running roughly from late June through late August or early September, depending on the year. The F347 road opens when conditions allow, and that timing shifts from one year to the next.

Midsummer brings the longest daylight, which matters in the highlands because afternoon light on rhyolite is worth having. July tends to offer the most stable conditions, though stable is not a word to apply loosely to highland weather. Early September is quieter and the low-angle light in late summer can be particularly good for the colors of the hillsides, but the window before roads close again is narrow, and early snowfall is possible.

Avoid attempting Kerlingarfjöll in conditions of low visibility. The geothermal terrain includes areas where the ground is unstable or hot enough to cause injury, and navigating unfamiliar volcanic terrain in thick fog is genuinely risky.

Tips and Responsible-Visitor Notes

A few practical points worth keeping in mind before you go.

  • Stay on marked trails in the geothermal zone. The crust in active geothermal areas can be thin, and stepping off the path introduces real risk. This is not cautionary boilerplate; burns from geothermal ground are a documented hazard in Iceland’s highland areas.
  • Bring wind and waterproof layers regardless of departure conditions. The central highlands generate their own weather, and the shift from warm sun to cold wind and rain can happen within an hour.
  • Water from the warm streams is not potable. The mineral content and geothermal inputs make it unsuitable for drinking. Carry enough water for your hike.
  • Book accommodation at the mountain hut well in advance if you plan to stay overnight. Capacity is limited and summer demand is consistent.
  • Do not attempt F347 without confirming road status. Check the official Vegagerðin road map on the day of your departure, not the day before.

The area around the huts has toilet and washing facilities during the summer season, but the hiking routes themselves do not. Plan accordingly and follow leave-no-trace principles when in the backcountry sections.

Kerlingarfjöll is not a place that forgives poor preparation, but it is also not unnecessarily hostile. Go with appropriate gear, realistic expectations about the weather, and enough time to move slowly through the geothermal valley, and the place will give back what you bring to it.