Krýsuvík is a sprawling geothermal area on the Reykjanes Peninsula, just 35 minutes from Reykjavík. Its most famous section, the Seltún geothermal field, is a landscape of bubbling mud pools, hissing steam vents, and earth painted in vivid yellows, reds, and greens by sulphur and mineral deposits. The area sits directly on the Mid-Atlantic Ridge fissure zone where the North American and Eurasian tectonic plates are pulling apart — the same geological forces that have triggered the recent Fagradalsfjall eruptions nearby. Unlike the Golden Circle's Geysir area, Krýsuvík is free to visit, rarely crowded, and feels genuinely otherworldly — like walking on a film set of an alien planet.
Story & Legend
The Krýsuvík area has been geothermally active for thousands of years, and the landscape changes constantly. In 1999, a borehole drilled in the area unexpectedly triggered a steam explosion that created a new mud pool. The broader Krýsuvík volcanic system covers a massive 350 square kilometres and extends 55 kilometres in length. The area gained renewed attention after the 2021 Fagradalsfjall eruption, as both sites lie along the same tectonic fissure zone. The German chemist Robert Bunsen — inventor of the Bunsen burner — visited Seltún in 1845 and used observations here to develop his theory on the formation of sulphuric acid. A few hundred metres from Seltún, the small Krýsuvíkurkirkja church was rebuilt in 2020 after the original 1857 structure burned down in 2010.
Geology & Science
Krýsuvík sits on a high-temperature geothermal field where underground water temperatures exceed 200°C. The vivid colours come from mineral reactions: yellow from crystallised sulphur, red and orange from iron oxides, and green from copper compounds and thermal algae. The Seltún field is the most accessible section, with elevated wooden boardwalks winding between fumaroles, boiling mud pools, and steaming vents. Nearby, the explosion crater lake Grænavatn ("Green Lake") gets its striking emerald colour from dissolved minerals and hot-spring algae — the colour shifts between green and blue depending on light conditions and season. The lake is 46 metres deep despite being only a few hundred metres in diameter. The larger Kleifarvatn lake, Iceland's largest on the Reykjanes Peninsula, lost 20% of its surface area after a magnitude 6.5 earthquake in 2000 opened cracks in its bed — it has been slowly refilling since.
Safety
Stay on the marked boardwalks and gravel paths at all times. The ground in geothermal areas is thin and fragile — it can collapse into scalding water without warning. The mud pools and hot springs are 80–100°C. The sulphur smell is strong but harmless in the open air, though people sensitive to fumes should avoid lingering directly over active vents. The boardwalk at Seltún is well maintained with two viewing platforms. The hike up to the solfatara on the hilltop above Seltún is steeper and unmarked — wear sturdy shoes and be cautious near the steam vents at the top. Parking is free at both Seltún and Grænavatn. There are no toilets or food facilities at the site — the nearest services are in Hafnarfjörður (20 minutes) or Grindavík (15 minutes).
Photo Tip
Visit on a sunny day for the most vivid mineral colours — the yellows and reds are dramatically more saturated in direct light. The boardwalks at Seltún provide elevated shooting positions that work well for wide-angle compositions showing the scale of the geothermal field against the surrounding hills. Steam rising from the vents creates atmospheric depth, especially in the morning when temperatures contrast is highest. Bring a polarising filter to cut through the steam haze and boost the mineral colours. The nearby Grænavatn crater lake is best photographed from the rim — the colour is most vibrant on calm days when the water is still. For the most dramatic shots, position the steam vents in the foreground with the coloured hills behind.
Insider Tip
Most visitors only see the Seltún boardwalk and leave. Spend an extra 30 minutes to explore the wider area: drive 2 minutes south to Grænavatn crater lake for the emerald green water, then continue to the Krýsuvíkurberg sea cliffs where thousands of seabirds nest in summer — guillemots, kittiwakes, and razorbills are common. The whole area makes an excellent half-day trip combined with Kleifarvatn lake (10 minutes north). If you're arriving or departing from Keflavík airport, Krýsuvík is a perfect first or last stop — it's only 25 minutes from the airport and avoids the Golden Circle crowds entirely.
Best Time to Visit
Year-round, but each season offers a different experience. Summer (June–August) has the most vivid colours and longest daylight for exploring the surrounding area. Winter offers dramatic steam contrasts against snow-covered terrain — the geothermal field looks like another planet. The site is rarely crowded at any time of year. Early morning or late afternoon light produces the best photography conditions. Avoid heavy rain days — the boardwalks can be slippery and the colours appear muted.
What to Bring
Sturdy walking shoes with grip — the boardwalks can be slippery when wet. A windbreaker is essential as the area is exposed. In winter, add warm layers and consider microspikes for icy sections. The sulphur smell doesn't cling to clothing. Bring a camera with a polarising filter for the best colour reproduction.
