
easy
3–4 hours
Suitable for people with basic fitness—able to hike 6 km with 330 m elevation gain on uneven terrain.
A short night hike from Hveragerði leads into Reykjadalur’s geothermal folds where a naturally warm river meets a sky dark enough for northern lights. Expect an easy but uneven 6 km route, a guided soak in mineral-rich water, and prime aurora viewing away from city glow.
The headlamp beam cuts a silver path through damp moss and steaming fissures as the guide slows at a ridge and tilts their face toward the sky. Above, the northern vault is a deep ink, pricked with stars; the valley sighs below with the steady hiss of geothermal breath. Walkers in layered jackets feel the ground pull warm and cool underfoot—the landscape itself alternates between invitation and warning, steam venting like an exhalation from the earth.

Night temperatures can drop quickly; bring a windproof, waterproof outer layer to stay warm between walks and the soak.
Trail is muddy with rocky sections—grippy hiking boots will keep you steady on the ascent and descent.
Pack a towel, swimsuit, and a complete change of clothes in a dry bag to stay comfortable after the hot river soak.
Choose operators that monitor KP index and weather; tours may be cancelled and refunded if aurora viewing isn’t realistic.
Hveragerði’s modern identity grew around geothermal greenhouse agriculture; locals have used hot spring heat for horticulture since the mid-20th century, creating a unique agricultural hub in subarctic Iceland.
Respect marked paths and avoid trampling geothermal features; the valley’s fragile soils and microbial mats recover slowly, so stay on trail and pack out all waste.
Grip and ankle support on muddy, rocky trail sections are essential for safety.
Retains warmth during pauses and while soaking—dry midlayers are critical post-soak.
fall specific
Needed for the naturally heated river; a quick-dry towel and dry bag make changes easier in cold weather.
Guides provide headlamps, but a personal light is helpful for extra visibility on the return.
winter specific