Kjölur or Sprengisandur: which highland crossing
Kjölur is bridged, shorter and has hot springs; Sprengisandur is emptier and harder. Both are summer only, and for most people a guided day is wiser.
The short version
- Both are F-roads, open roughly late June or early July to September, depending on snow. Check road.is on the day.
- Kjölur (F35) runs from Gullfoss to Blöndudalur. Its rivers are bridged; the draws are Kerlingarfjöll and Hveravellir.
- Sprengisandur (F26) runs between Hrauneyjar and Bárðardalur. It's longer, rougher, and empty for most of its length.
- Neither has fuel along the way, and rental insurance does not cover river or gravel damage.
- The easiest way to see Kjölur is a guided day from Reykjavík, from €286.
Pick Kjölur. It’s shorter, every river on it is bridged, and there are two things worth stopping for along the way: Kerlingarfjöll and the hot pool at Hveravellir. Sprengisandur is for people who want the emptiest drive in Iceland and are comfortable driving it. It is a road through a desert, and that’s the whole point.
Both cross the interior between the south and the north, and both are summer-only F-roads. They open when the snow and meltwater allow, usually late June or early July, and close again in September. Snow in August is possible on either. Check road.is the morning you go, not the week before.
Kjölur — F35
Kjölur leaves the Golden Circle just past Gullfoss and runs north between two ice caps, Langjökull on the left and Hofsjökull on the right, to Blöndudalur near Blönduós. It’s around 165 km of highland gravel, three to four hours of driving without stops.
What makes it worth doing is what’s just off it. Kerlingarfjöll is a range of red and yellow rhyolite mountains with steaming ground, reached on a spur road. Hveravellir, further north, is a geothermal field with a natural bathing pool and a small hut and café. Between them it’s black gravel, glacier views and very little else.
It’s the easier road. The surface can still be rough and corrugated, and you’ll want a 4x4 because the law requires one on any F-road. But you won’t be fording rivers.
Sprengisandur — F26
Sprengisandur starts in the south at Hrauneyjar, north-east of Hekla, and runs north between Hofsjökull and Vatnajökull to Bárðardalur, about 40 minutes from Goðafoss. It’s longer than Kjölur, around 200 km of highland road, and slower: five to six hours is realistic.
The landscape is a grey-brown stone desert with glaciers on the horizon on both sides. There is one staffed hut area at Nýidalur, roughly halfway. There’s no hot pool, no café and, most of the way, no one. At the northern end, Aldeyjarfoss falls over basalt columns and is the one sight most people stop for.
The road has some fords, usually small, but it’s rougher in general, and a breakdown out here is a long wait. It isn’t a road to try in your first week of driving in Iceland.
The rental car question
Most rental contracts allow F-roads only in a 4x4, and exclude damage from river crossings, gravel and the underside of the car. That exclusion applies even on Kjölur. There is no fuel on either road between Hrauneyjar or Gullfoss and the north, so fill up before you leave.
If you’re driving the ring road and want one highland day, Kjölur with a night near Kerlingarfjöll is manageable in a decent 4x4. Sprengisandur means planning, a full tank and someone in the car who knows what they’re doing.
Guided options
For most people the sensible way to see Kjölur is Kjölur & Golden Circle, from €286. Fourteen hours from Reykjavík, summer only, with Gullfoss, Geysir and Þingvellir at the ends and Kerlingarfjöll in the middle. It’s a very long bus day, and you won’t have long at any one stop. You also won’t be the one driving it.
For a taste of the Sprengisandur side without crossing, Landmannalaugar and the Valley of Tears is from €196 for eleven hours. It goes in past Hrauneyjar to Sigöldugljúfur and Landmannalaugar, near where F26 begins.
Two multi-day options cross Sprengisandur in full. The 3-Day Rafting Expedition (price on request, adults only) drives into the desert to raft the East Glacial River. Secrets of the Highlands is from €18,975, a ten-day private trip with a driver and photographer that takes both roads.
Our honest take
If you have one highland day and no 4x4 experience, book the Kjölur day tour and let someone else drive. You’ll see Kerlingarfjöll and be back in Reykjavík by night.
If you’re self-driving the north and south anyway and want to cut across, take Kjölur and stop at Hveravellir. It’s the better road for almost everyone.
Drive Sprengisandur only if the emptiness is what you’re after, and only in a proper 4x4 with a full tank and a plan. It’s a remarkable drive. It’s also a long day of grey gravel, and if the cloud is down you’ll see very little of the glaciers that make it special.
