Reykjadalur Valley features a natural hot spring river reached via a scenic hike near Hveragerði. This guide covers the trail, difficulty, and what to expect on the way.
Reykjadalur, meaning Steam Valley in Icelandic, is one of the best free experiences in Iceland. The hike takes you 3 km into an active geothermal valley where a naturally heated river runs at 36 to 40°C. There is no entrance fee, no concrete spa complex, and no wristband. You hike to it, change on a wooden platform, and get in a river that is warm because the earth beneath it is.
Most visitors from Reykjavik combine this with the Golden Circle return via Route 1, making it a natural end-of-day stop on one of Iceland's busiest driving routes.
Trail Facts at a Glance
Distance: 6 km round trip (3 km each way)
Elevation gain: Approximately 200 meters
Difficulty: Moderate
Time: 45 to 75 minutes each way, 2 to 3 hours total, including bathing
Cost: Free
Open: Year-round, 24 hours
Trailhead: Reykjadalur car park, approximately 2 km north of Hveragerði town center
GPS: 64.0229° N, 21.2116° W
How to Get There
The trailhead is 45 km southeast of Reykjavik via Route 1. Take Route 1 toward Selfoss, then follow signs to Hveragerði. The Reykjadalur car park is approximately 2 km north of the town center, well-signed from the main road.
The car park has toilets and a small cafe at the trailhead. It fills quickly on weekends and sunny summer days. Arriving before 9 AM or after 5 PM gives you a significantly better chance of finding a space without waiting.
Without a car, Strætó buses run from Reykjavik to Hveragerði every 3 hours. From the town center, you can walk to the trailhead, which adds approximately 3.2 km each way to the total hike, or take a taxi for the 2 km to the car park.
The Trail: What You Actually Walk Through
The trail starts at the car park and immediately crosses a bridge over a small river before heading uphill on a gravel path along Rjúpnabrekkur, the Ptarmigan Slopes. The first section is the steepest part of the hike. It takes about 15 to 20 minutes to clear the initial ascent.
After the slope, the terrain levels and the geothermal character of the valley begin. Hot spring vents and mud pools appear on the left side of the trail. Steam rises from cracks in the hillside. The smell of sulphur is present throughout but most noticeable near the active vents. Boardwalks cross the most delicate geothermal ground sections. Stay on the marked paths: the ground between hot spring areas can be thin above boiling water below.
About halfway up, Djúpagilsfoss waterfall is visible from a viewpoint above the valley. The trail continues upward through increasingly dramatic steam vent territory. In cold weather, the steam clouds from the vents can be dense enough to obscure visibility for a few seconds as you walk through them.
The river appears at the top of the valley at a location called Klambragil. Wooden bathing platforms with basic changing dividers line the bank. The water temperature varies along the river's length: hotter upstream, where geothermal springs feed directly into the river, and cooler downstream, where cold water mixes in.
The River Bathing Experience
There is no managed changing facility beyond the wooden platforms on the bank. You change at the riverside, leave your bag on the platform or bank, and wade in from the shore. The river bottom is rocky and uneven. Entry takes a moment of careful footing before you settle into the water.
The temperature on a summer day runs around 38 to 40°C in the hottest sections near the springs, dropping to 36 to 37°C in the middle sections that most people find most comfortable. The further downstream you go, the cooler it becomes. Finding your ideal temperature spot takes a few minutes of walking the bank and testing different sections.
The river is not wide and not long, but it accommodates a reasonable number of visitors spread across its length. On busy summer days, it can be crowded at peak hours between 11 AM and 3 PM. Visiting in the early morning or evening avoids the main tourist window and gives you a quieter experience.
What to Bring
The trail requires nothing specialized in summer, but a few items make a genuine difference.
Swimsuit: There is nowhere to buy one at the trailhead
Towel: Also not available at the site, and you will need it
Dry bag or waterproof bag for your phone and valuables at the riverside
Waterproof trail shoes or hiking boots: The path is gravel and can be muddy, with water crossings near the bathing area
Warm clothing layers for after the bathing: Stepping out of 38°C water into Icelandic wind cools you quickly
Water and snacks: The hike is not long but the bathing stop extends the outing to 2 to 3 hours
In winter, add microspikes that clip over your boots. The trail becomes icy in places from November through March, and the ascent section in particular requires traction on hard-packed ice.
Best Time to Visit Reykjadalur
The trail is open year-round. The experience differs significantly by season.
Summer from June through August is the most comfortable and the most crowded. The trail is clear, the valley is green, and the contrast between the warm river and cool air is milder than in winter. Arrive early to avoid the peak hour rush at the river.
Winter from November through March is the most dramatic. Cold air around the valley amplifies the steam from every vent, creating cloud-like atmospheric conditions throughout the hike. The river at 38°C, surrounded by snow and ice, with steam rising across the valley, is one of Iceland's genuinely specific winter experiences. The trail requires microspikes and careful footing. Some sections of the path ice over, and the ascent needs attention.
September and October bring falling temperatures, quieter visitor numbers, and autumn colors across the hillsides. Many visitors rate shoulder season as the best Reykjadalur experience.
Combining Reykjadalur With Other Activities
The most natural combination is a Golden Circle day ending at Reykjadalur. The Golden Circle clockwise loop from Reykjavik covers Þingvellir, Geysir, and Gullfoss, then returns via Route 35 to Route 30 to Route 1 toward Hveragerði. Reykjadalur sits directly on the return road, adding 2 to 3 hours to the day before the final 45-minute drive back to Reykjavik.
Hveragerði town itself has a small geothermal center and good cafes. After the hike, eating in Hveragerði before the return drive is a more relaxed option than heading straight back on Route 1.
Ölverk pizza and brewery in the town serves wood-fired pizza and geothermally brewed beer and is consistently rated as one of the better meals in the Hveragerði area.
Safety Notes for the Hike
The geothermal ground in the valley is genuinely hazardous if you leave the marked path. Thin crusts above boiling water or mud exist in the areas between active hot springs. The boardwalks and marked trails exist for this reason. Stay on them throughout the hike.
The hot spring vents and mud pools visible from the trail are not safe to touch or enter. The water in the vents is significantly hotter than the river. The only bathing area is the river section at the top of the valley where the water has cooled to a safe temperature.
The river entry is on uneven rocky ground. Take your time getting in, particularly if conditions are slippery. There is no rescue service on site.
Guided Tours vs Self-Driving to Reykjadalur
Self-driving is the most practical option for the large majority of visitors. The trailhead is 45 minutes from Reykjavik on a paved road; the car park is well-signed, and no specialist vehicle is required at any time of year.
Several Reykjavik tour operators run guided hikes to Reykjadalur with transport included. These suit visitors without a rental car or those who want a guide to explain the geothermal geology en route.
The hike itself is straightforward enough that a guide is not necessary for navigation, but the geological and historical commentary adds value for visitors interested in understanding what they are walking through.
