Iceland's Geothermal Wonders: What to See and How They Work

Iceland sits on the Mid-Atlantic Ridge, the boundary where the North American and Eurasian tectonic plates slowly pull apart. Magma rises to fill the gap, and the result is one of the most geothermally active places on earth. You feel it everywhere here. Steam rises from cracks in the ground. Rivers run warm. The smell of sulphur greets you before you even see the source.

This guide covers the best geothermal sights you can visit in Iceland, from erupting geysers to alien-looking mud fields to mountains painted by volcanic minerals over thousands of years. These are places to watch, walk through, and photograph. If you want to actually soak in hot water, head to our guide to the best hot springs in Iceland.

Why Iceland Is So Geothermally Active

The short version: Iceland sits on top of a crack in the earth's crust. The Mid-Atlantic Ridge runs right through the country from southwest to northeast. This is where two tectonic plates are pulling apart at roughly 2 centimetres per year. As they separate, magma pushes up from below, and that heat is what powers everything you will see in this article.

Iceland is one of the few places on earth where this mid-ocean ridge rises above sea level. That is why you can stand here and literally watch the planet's interior forces at work, something that normally only happens deep on the ocean floor.

The numbers are staggering. Iceland has over 600 hot springs and more than 200 volcanic systems. About 30 of those volcanic systems are considered active. The island produces so much geothermal energy that it heats roughly 90% of Icelandic homes directly from the ground. No gas boilers, no oil furnaces. Just hot water piped from deep wells.

All of this means that no matter where you are in Iceland, you are never far from some kind of geothermal activity. But some places concentrate it in ways that are genuinely spectacular.

Geysers

Strokkur

Strokkur is probably the most reliable natural show in Iceland. This geyser sits in the Haukadalur Valley on the Golden Circle route, and it erupts every 5 to 10 minutes, shooting a column of boiling water 15 to 30 metres into the air.

The eruption itself is mesmerising. The water in the basin starts to dome upward, forming a blue-green bubble that holds for half a second before exploding into a white column of steam and spray. It happens fast. If you blink at the wrong moment, you miss the best part.

Practical details:

• Location: Haukadalur Valley, right off Route 35 on the Golden Circle
• Cost: Free. You just park and walk over
• Best time: Before 10am, when the tour buses start arriving. Early morning light is also better for photos
• Tip: Stand on the upwind side. The spray carries, and getting hit with near-boiling water and wind is not pleasant
• Time needed: 20 to 30 minutes is enough to see several eruptions

The Original Geysir

The word "geyser" in English comes from this exact spot. Geysir (from the Icelandic word "geysa," meaning to gush) was once the most famous erupting hot spring in the world. European travellers described it in the 1800s, and the name stuck for every similar feature on the planet.

These days, Geysir is mostly dormant. It erupts rarely and unpredictably, sometimes going years between eruptions. Earthquakes can briefly wake it up, but you should not visit expecting to see it go off. What you will see is the large, steaming pool itself, surrounded by mineral-stained ground and smaller hot springs. It is still impressive, just in a quieter way than its neighbour Strokkur.

How Geysers Work

A geyser needs three things: a heat source, water, and a natural plumbing system that traps that water underground. In Iceland, the heat comes from magma close to the surface. Groundwater seeps down through rock, gets superheated past its normal boiling point (the pressure underground keeps it liquid), and builds up pressure until it finds a way out. When it finally erupts, the sudden pressure drop causes all that superheated water to flash to steam at once, and you get the explosive column.

Strokkur is so regular because its underground chamber is the right shape and size to refill and reheat on a consistent cycle. Geysir's plumbing is more complex and partially blocked by mineral deposits from centuries of eruptions. That is why it has become unpredictable.

Steam Vents, Fumaroles, and Mud Pots

Hverir / Namaskard (Myvatn Area, North Iceland)

If you only visit one geothermal area beyond the geysers, make it Hverir. This place looks like another planet. The ground is stained in shades of yellow, orange, and grey. Mud pots bubble and pop with thick, grey clay. Steam vents hiss from cracks in the earth. The air smells strongly of hydrogen sulphide, which is the rotten-egg smell that follows you around most geothermal areas in Iceland.

Hverir sits in the Namaskard pass, right off Route 1 (the Ring Road) near Lake Myvatn in North Iceland. You can see the yellow hillside and rising steam from the road before you even reach the car park.

Practical details:

• Location: Route 1, about 5 km east of Reykjahlid (the main town at Lake Myvatn)
• Cost: Free
• Time needed: 30 to 60 minutes to walk the whole area
• Safety: This is important. Stay on the marked paths. The ground looks solid in many places but can be a thin crust over boiling water or scalding mud. People have been seriously burned stepping off the trails
• The smell: Yes, it is strong. You get used to it after about 5 minutes. It will not harm you unless you stand directly over a vent for a long time
• Nearby: Myvatn Nature Baths are just 15 minutes away if you want to soak afterward (see our hot springs guide)

Seltun / Krysuvik (Reykjanes Peninsula)

Seltun is the geothermal area most accessible from Reykjavik. It is only about 40 minutes from the city on the Reykjanes Peninsula, and it packs a surprising amount of activity into a compact area.

A wooden boardwalk takes you through bubbling mud pots, hissing steam vents, and ground painted in blues, greens, and rusty reds by mineral deposits. The scale is smaller than Hverir, but the colours are more vivid, and you can get closer to the features from the boardwalk.

Practical details:

• Location: Off Route 42 on the Reykjanes Peninsula
• Cost: Free
• Time needed: 20 to 40 minutes
• Combine with: Kleifarvatn lake (a dark, mysterious lake with no visible inlet or outlet) and the town of Grindavik
• Less crowded than Haukadalur, especially outside of summer

Haukadalur Valley (Beyond the Geysers)

Most visitors to the Geysir area watch Strokkur erupt a few times, take some photos, and get back on the bus. But the entire Haukadalur Valley is a geothermal area worth exploring. Walk past Geysir and you will find smaller hot springs, colourful mineral deposits, and steam vents scattered across the hillside.

The ground shifts from green grass to orange and white mineral crust within steps. Small pools of vivid blue water sit alongside patches of bare, steaming earth. If you take 15 to 20 minutes to walk the trails beyond the main geyser viewing area, you will see features that most visitors completely miss.

Colourful Geothermal Landscapes

Landmannalaugar (Highlands)

Landmannalaugar is where geothermal activity becomes landscape art. The mountains here are made of rhyolite, a type of volcanic rock that reacts with geothermal minerals over thousands of years to produce colours you would not believe are natural. Red, green, yellow, purple, and orange streak across the hillsides in patterns that change with the light.

The area sits in the Fjallabak Nature Reserve in the Highlands of Iceland. Getting there is part of the experience, as the road crosses rivers and black sand deserts.

Practical details:

• Location: Fjallabak Nature Reserve, Highlands
• Access: F-road (F208 or F225), which means 4x4 only. Open roughly late June to September depending on conditions. You can also take a bus from Reykjavik (several companies run scheduled services in summer)
• Cost: Free to visit. Camping fee if you stay overnight
• Time needed: A full day minimum. Many people stay 2 to 3 days to hike
• There is a natural hot spring at Landmannalaugar where hot and cold streams meet. Brief soak, stunning setting (more in our hot springs guide)
• This is also the starting point of the famous Laugavegur hiking trail to Thorsmork

Kerlingarfjoll (Highlands)

Kerlingarfjoll gets a fraction of Landmannalaugar's visitors, but the geothermal scenery is equally jaw-dropping. Steaming valleys wind between colourful peaks, with hot springs bubbling up through the rock and snow lingering on the higher slopes even into July.

The Hveradalir geothermal area within Kerlingarfjoll is the highlight. A trail loops through a valley of steaming vents, bright mineral deposits, and small boiling pools, all framed by snow-streaked mountains. It feels remote in a way that Landmannalaugar does not, partly because far fewer people make the journey.

Practical details:

• Location: Central Highlands, off the Kjolur highland road (Route 35 / F35)
• Access: 4x4 required. The road usually opens in late June
• Accommodation: Kerlingarfjoll Highland Resort offers huts and camping
• Time needed: At least half a day for the Hveradalir trail. Ideally overnight
• Less infrastructure than Landmannalaugar, more solitude

Geothermal Energy in Action

Hellisheidi Power Plant (ON Power)

Iceland does not just look at its geothermal energy. It uses it. The Hellisheidi Geothermal Power Plant, about 20 minutes from Reykjavik, is one of the largest geothermal power stations in the world. It produces both electricity and hot water for the capital area.

The plant has a visitor centre where you can learn how geothermal energy is captured and converted. The exhibits explain the process clearly without being dumbed down, and you can see the actual machinery through viewing windows.

Hellisheidi is also home to the Carbfix project, which dissolves CO2 in water and injects it into basalt rock underground. Within two years, the CO2 mineralises and turns to stone. It is one of the most promising carbon capture approaches in the world, and it is happening right here.

Practical details:

• Location: Route 1, about 20 minutes east of Reykjavik
• Cost: Entrance fee for the visitor centre (check their website for current prices)
• Time needed: 1 to 1.5 hours
• Good rainy day activity

How Geothermal Heats Icelandic Homes

When you turn on the hot tap in an Icelandic bathroom, the water comes straight from the ground. Not heated by a boiler. Not warmed by gas. Actual geothermal water, pumped from wells deep in the earth, piped through the district heating system, and delivered to your shower.

That faint sulphur smell you notice in the hot water? That is the geothermal source. Icelanders are so used to it they do not even notice anymore. Visitors sometimes worry something is wrong with the plumbing. Nothing is wrong. That is just what water from deep in the earth smells like.

Here is a fun fact about Reykjavik itself: the name means "Smoky Bay." When the first Norse settlers arrived around 870 AD, they saw steam rising from the ground along the shoreline and thought the bay was smoking. It was not smoke. It was geothermal steam, the same energy source that now heats the city.

Safety Around Geothermal Areas

Geothermal areas are beautiful, but they are genuinely dangerous if you leave the marked paths. This is not an exaggeration. Every few years, someone gets seriously burned in Iceland by stepping off a trail in a geothermal zone.

The rules are simple:

• Stay on marked paths and boardwalks. Always. No exceptions. The ground in geothermal areas can look solid but be only a thin crust over boiling water or scalding mud. You cannot tell by looking at it
• Do not touch the water. Water in active geothermal areas is often 80 to 100 degrees Celsius. Do not dip your hand in to test it. Do not let children near the edges
• Watch for sulphur fumes. The hydrogen sulphide gas at places like Hverir can be strong. If you start to feel dizzy or light-headed, move upwind or away from the vents. In normal outdoor concentrations it is not dangerous, but standing directly over a vent is not wise
• Keep children close. Small children do not understand that the pretty coloured ground is dangerous. Hold hands, stay on paths
• Do not throw anything into geothermal features. No coins, no rocks, no rubbish. These are natural systems, and foreign objects can damage them or alter their behaviour

These rules apply everywhere, from the busy boardwalks at Geysir to the remote highlands. The geology does not care how experienced you are.

Where to Go From Here

Iceland's geothermal activity is not just scenery. It powers the country, shapes the land, and reminds you that you are standing on a living island that is still being built by forces from deep underground. Whether you watch Strokkur erupt, smell the sulphur at Hverir, or walk through the painted mountains of Landmannalaugar, you are experiencing something most of the world only reads about.