Boardwalk
~15–30 min loop
Well-maintained boardwalk through the heart of the geothermal field
Krýsuvík-Seltún: Colorful Geothermal Area on Reykjanes
A geothermal field of bubbling mud and steaming vents, its ground stained yellow, orange, red, and green by sulfur and mineral deposits.
Location
Route 42
Reykjanes Peninsula • Near Kleifarvatn
Quick Answer
Krýsuvík-Seltún is a geothermal field on the Reykjanes peninsula with bubbling mud pots and mineral-stained ground. Free entry; the boardwalk starts on Route 42.
Krýsuvík-Seltún is one of the most colorful geothermal areas in Iceland, located along Route 42 on the Reykjanes peninsula, just south of Kleifarvatn lake. The Seltún field is compact but very active: bubbling mud pots, hissing fumaroles, and steaming vents, set against ground stained yellow, orange, red, and green by sulfur and iron oxide deposits. A well-built boardwalk loop lets visitors walk safely through the middle of the field and see the features up close. The area is part of the larger Krýsuvík volcanic system, one of several active systems on the Reykjanes peninsula. Easy access from Reykjavík and the colors make it one of the most visited geothermal stops on the peninsula.
Sources and page update
Updated: 2026-09-10
Stay on boardwalks. Boiling mud and scalding steam present throughout the area. Ground outside the boardwalk is unstable and potentially dangerous. Check volcanic alerts for Reykjanes.
For sourcing standards and how to report an error, see the editorial policy.
Official sources to check
Entrance Fee
Free
Open year-round with parking and restroom facilities
Distance
~40 km
From Reykjavík via Route 42, about 40 minutes’ drive
What to Expect
Vivid Mineral Deposits
Sulfur (yellow), iron oxide (red/orange), silica (white), and clay minerals (green) coat the ground; the colors are most vivid after rain
Bubbling Mud Pots (100°C)
Thick, gurgling pools of hot gray mud at approximately 100°C popping and splattering as volcanic gases escape from below the surface
Free Admission & Boardwalk
Completely free to visit year-round. A well-maintained boardwalk loop with information boards takes 15-30 minutes to walk at a leisurely pace
What to Bring
Sturdy footwear with good grip (boardwalk can be slippery when wet), windproof jacket (Reykjanes is windy), and a camera
Kleifarvatn Lake Nearby
Iceland's deepest lake (97 m) lies just north of Seltún and has underwater hot springs. The dark lake is a worthwhile photo stop on Route 42
Grænavatn Crater Lake
A green crater lake just east of Seltún. Its color comes from algae, sulfur compounds, and mineral deposits
Getting There
From Reykjavík, take Route 41 south toward Hafnarfjörður then continue onto Route 42, which crosses the Reykjanes peninsula. Krýsuvík-Seltún is located directly on Route 42 between Kleifarvatn lake and the south coast, approximately 40 km (40 minutes) from central Reykjavík. A free parking area is right beside the road with restroom facilities. No 4WD required; the route is paved or well-maintained gravel throughout. The nearest town is Hafnarfjörður (30 km). Combine with Kleifarvatn lake (5 minutes north), Grænavatn (2 minutes east), and Gunnuhver (30 minutes west) for a full Reykjanes geothermal day trip.
Best Time to Visit
Year-round. The mineral colors are most vivid after rain when wet ground intensifies the hues. June through August: longest daylight, mildest conditions, and best photography light. Summer afternoons see the most visitors, but it rarely gets as crowded as Golden Circle attractions. September through October: fewer people. November through February: the steam stands out against dark winter skies. The boardwalk can be icy, so wear sturdy footwear with good grip. On clear winter nights, the Reykjanes peninsula is a good spot for northern lights. March through May: spring light returns with moderate visitor numbers. Morning visits are quietest in any season.
Seltún is one stop within Krýsuvík
The names do not describe two separate trips. Visit Reykjanes lists Seltún among several geothermal areas within Krýsuvík. For the familiar boardwalk among mud pots and fumaroles, use the Seltún parking location on Route 42.
A longer Krýsuvík walk is a separate route-planning decision. Do not follow steam across unmarked ground to connect the geothermal areas. Seltún lies within Reykjanes nature reserve, and the boardwalk provides the intended way to examine its mineral deposits.
Planning help
Kr\u00fdsuv\u00edk-Selt\u00fan FAQs
Quick answers with safety notes where it matters.
Is there an entrance fee at Krýsuvík-Seltún?
No, Krýsuvík-Seltún is free to visit. There is a parking area beside Route 42 with restroom facilities. The boardwalk loop through the geothermal area is open year-round. It is one of the most accessible geothermal sites in Iceland, requiring no hiking or special vehicle.
How long does it take to visit Krýsuvík-Seltún?
The boardwalk loop takes about 15–30 minutes to walk. The area is compact but photogenic, so many visitors spend 30–45 minutes total. It combines well with other Reykjanes attractions like Grænavatn (Green Lake), Gunnuhver, and the Kleifarvatn lake for a full day trip.
Why are the rocks so colorful at Seltún?
The vivid colors come from mineral deposits created by geothermal activity. Yellow and greenish tones are from sulfur, reds and oranges from iron oxides, and white patches from silica and clay. Chemical reactions between hot gases and the surrounding rock keep the colors changing. They are most vivid when the ground is wet.
Is Krýsuvík affected by the recent Reykjanes eruptions?
Krýsuvík sits within the broader Reykjanes volcanic system that has been active in recent years. While the recent eruptions (near Fagradalsfjall and Sundhnúkur) occurred in different fissure systems on the peninsula, the entire Reykjanes area is tectonically connected. Always check SafeTravel for current volcanic alerts before visiting any Reykjanes location.
For a countrywide view of Iceland’s volcanic systems, explore our Iceland statistics.