Natural Hot Spring
Reykjadalur
South Iceland
Reykjadalur, or 'Steam Valley,' is a remarkable geothermal attraction in South Iceland, where the earth's raw volcanic forces are vividly displayed. Hike through a dramatic landscape of steam vents and boiling pools, culminating in a unique opportunity to bathe in a naturally heated river. The cascading waters seen in the image flow through mineral-rich terrain, offering a truly immersive wilderness experience.
Hike into a steaming volcanic valley and bathe for free in a genuinely warm wild river — one of Iceland's most rewarding combinations of trail and thermal water.
Story
Reykjadalur — "Steam Valley" — is the geothermal area above Hveragerði where a genuinely warm river runs through a landscape of hissing fumaroles, bubbling mud and mineral-stained hillsides fed by the Hengill volcanic system. Unlike most of Iceland's hot springs, this one asks something of you first: reaching the bathing stretch of the Reykjadalsá river means an uphill walk of roughly 3.5 km, commonly taking 45 minutes to an hour each way, from the car park above Hveragerði. The reward is a wooden boardwalk along a bend in the river where the water settles into a comfortable soaking temperature — cooler as side streams join further downstream, hotter the further upstream you wade — so bathers spread out along the bank until they find their own spot. There are no lockers, cafés or toilets at the river itself, only simple wooden screens for changing, which is part of the valley's appeal: after the climb, this remains one of the only places in Iceland to bathe for free in a genuinely wild hot river.
History
Reykjadalur sits within the Hengill volcanic system, whose geothermal heat has shaped the whole Hveragerði area — a town that grew up in the early 20th century around greenhouses warmed by the same underground water and is still known informally as Iceland's hot-spring capital. The district's geothermal activity is not static: a magnitude 6.3 earthquake struck close to Hveragerði on 29 May 2008, and earthquakes of this kind are documented to alter hot-spring behaviour locally, opening new vents in some places while changing or drying up others.
Did You Know?
The river gets hotter the further upstream you wade and cooler downstream as side streams join in, so bathers walk along the bank until they find their own comfortable spot rather than relying on one fixed pool.
Admission
Free (small parking fee at the trailhead)
Practical Information
Best Time
June to October for the easiest, driest hiking conditions; winter visits are possible but the trail can be icy and dangerous, so bring crampons/microspikes and extra caution.
Duration
Half a day — allow 2.5–3.5 hours round trip including time in the water.
Getting There
The trailhead car park sits above Hveragerði, about 45 minutes from Reykjavík by car along Route 1; from the car park, follow the marked trail roughly 3.5 km uphill to the bathing area.
Transport
Self-drive to the Reykjadalur car park, or join a guided hiking tour from Reykjavík or Hveragerði; no public bus runs directly to the trailhead.
Budget
Free to hike and bathe; parking at the trailhead costs a small fee (commonly cited around 300–1,000 ISK depending on duration).
Frequently Asked Questions
How long is the hike to the bathing area?+
From the car park above Hveragerði it's about 3.5 km (2.2 miles) one-way, commonly taking 45 minutes to an hour uphill; the walk back down is faster.
Is the whole river safe to bathe in?+
No — only the marked, boardwalked stretch is intended for bathing. Water elsewhere in the valley, including pools and mud near the trail, can be scalding hot, and the ground off-trail can hide unstable, boiling ground. Stay on the marked path and only enter the water at the designated bathing area.
What facilities are at the bathing area?+
Very basic ones — a boardwalk and simple wooden privacy screens for changing along the riverbank. There are no toilets, lockers or cafés at the river itself; those are back at the trailhead car park.
Is there an entrance fee?+
No, Reykjadalur and its hot river are free to visit. There is a small paid parking fee at the trailhead car park.
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