Kerlingarfjöll Loop (F347/F735)

The steam rises from Hveradalir like smoke signals from the earth’s core, and if you’re driving the Kerlingarfjöll Loop on a clear July morning, you’ll see it against the rhyolite peaks long before you reach the geothermal valley itself. This 37-mile highland loop through Iceland’s volcanic interior demands respect—the F347 and F735 mountain tracks climb to 4,265 feet through terrain that will test both your rig and your nerve. You need high-clearance 4WD minimum, preferably with all-terrain tires and recovery gear, because the loose volcanic gravel and river crossings don’t forgive lazy driving.

The route cuts through the Kerlingarfjöll mountain range, where troll-shaped peaks oversee a landscape that looks more Mars than Earth. You’ll ford multiple glacial streams that can rise without warning—check conditions at the ranger station near Gullfoss before heading up. The track itself shifts between technical rock sections and deep gravel that can swallow a wheel if you’re not reading the terrain. Plan for 6-8 hours of driving time, though most people camp overnight at the designated areas near the geothermal fields. No cell service exists beyond the access roads, and fuel stops are back in the lowlands, so top off your tanks and carry extra water.

July through September offers the only reliable window when snow doesn’t block the passes, but even then, weather changes fast at altitude. The payoff justifies the punishment—boiling hot springs, steaming fumaroles, and otherworldly rhyolite formations that photographers and geologists travel continents to witness. You’ll share the highlands with maybe a dozen other vehicles on busy days, compared to the tour bus parades at the Ring Road attractions below.

This isn’t a trail you run for bragging rights or Instagram shots. The Kerlingarfjöll Loop rewards drivers who want to experience Iceland’s raw volcanic power without crowds, who don’t mind fixing a flat tire with sulfur steam in their face, and who understand that the best adventures happen where the pavement ends and the cell towers can’t reach. Have a dirty day.