Exploring Iceland’s Caves
Iceland sits on one of the most volcanically active spots on Earth, and thousands of years of eruptions, glacial movement and geothermal activity have carved an extraordinary underground world beneath the surface. From glowing blue ice caves inside Europe's largest glacier to ancient lava tubes stretching for kilometres beneath moss-covered fields, Iceland's caves offer some of the most otherworldly experiences you can have anywhere on the planet.
The best part? You do not need to be an experienced caver to explore them. Most of Iceland's caves are accessible through guided tours that welcome beginners, families and anyone who does not mind wearing a helmet for an hour or two. Whether you are visiting in winter for the famous ice caves or in summer for the lava tubes, there is always something extraordinary waiting underground.
Types of Caves in Iceland
Iceland has three main types of caves, and each offers a completely different experience.
Ice caves form inside glaciers when meltwater carves tunnels through the ice. They are seasonal, typically accessible from November to March, and their appearance changes every year. The ice can glow in shades of electric blue, white and black depending on the density of the ice and the amount of volcanic ash trapped inside. No two visits are ever the same, because the caves literally reshape themselves each season.
Lava tubes are created when the outer surface of a lava flow cools and hardens while molten lava continues flowing underneath. When the eruption stops, the lava drains out and leaves a hollow tunnel behind. Iceland has some of the longest and most impressive lava tubes in Europe, and many of them are thousands of years old. Unlike ice caves, lava tubes are stable and accessible year-round.
Volcanic and geothermal caves include everything from small steam-carved cavities near hot springs to the famous Grjótagjá cave near Mývatn, where a geothermal hot spring sits inside a lava formation. These tend to be smaller and more intimate, and some have fascinating cultural histories tied to Icelandic sagas and folklore.
The Best Caves to Visit in Iceland
Vatnajökull Ice Caves (Southeast Iceland)
The ice caves inside Vatnajökull glacier are the ones you have probably seen on Instagram, and they genuinely live up to the photos. These natural caves form each autumn as glacial rivers carve new tunnels, and guides spend weeks scouting for safe, accessible formations before the season opens.
The ice ranges from crystal clear to deep sapphire blue, and in some caves you can see layers of volcanic ash from past eruptions sandwiched between the ice. On bright days, sunlight filters through the thinner sections and the entire cave glows.
Season: November to March only. The caves are not safe in warmer months when meltwater is active.
Access: Tours depart from Jökulsárlón glacier lagoon, typically including a super jeep ride and a short hike to the cave entrance. Expect 3 to 4 hours total, with 30 to 45 minutes inside the cave itself.
Cost: Around 20,000 to 25,000 ISK per person. Book well in advance, as these tours sell out weeks ahead during December and January.
Difficulty: Moderate. You will hike over uneven glacier terrain wearing crampons (provided). A reasonable level of fitness is needed, but no climbing experience is required.
Katla Ice Cave (Near Vík)
If you are visiting outside the traditional November to March ice cave season, or if Vatnajökull tours are sold out, the Katla ice cave is an excellent alternative. Located inside the Mýrdalsjökull glacier near the Katla volcano, this cave tends to be accessible for a longer season, sometimes year-round depending on conditions.
The ice here has a distinctly different character from Vatnajökull. Because Katla is an active volcano, the ice is streaked with dark volcanic ash, creating dramatic black and white patterns. It feels more raw and geological, less "fairy tale blue" and more "inside a volcano."
Access: Super jeep tours depart from Vík. The drive across the glacier in a modified truck is an adventure in itself.
Cost: Around 25,000 to 30,000 ISK per person. The higher price reflects the longer super jeep journey.
Difficulty: Easy to moderate. Less hiking than Vatnajökull tours. Suitable for most fitness levels.
Raufarhólshellir (The Lava Tunnel)
This is the most accessible cave in Iceland and the one I would recommend if you only have time for one underground experience. Located just 30 minutes from Reykjavík, Raufarhólshellir is a 1,360-metre lava tube formed during an eruption roughly 5,200 years ago.
The tunnel is impressively large, up to 30 metres wide and 10 metres high in places, with a well-built walkway and lighting that makes it feel more like visiting an underground cathedral than going caving. The deeper sections of the cave contain stunning ice formations and lava stalactites that look like they belong on another planet.
Two tours are available: the Standard Tour (1 hour, follows the illuminated walkway) and the Extreme Lava Caving Tour (3 to 4 hours, goes beyond the walkway into the unlit sections with headlamps and more challenging terrain).
Access: Drive yourself (Route 39, well signposted) or join a guided tour from Reykjavík.
Cost: Standard tour around 6,990 ISK. Extreme tour around 19,900 ISK. Significant price difference, but the standard tour is excellent value and suitable for all ages.
Difficulty: Standard tour is easy. Suitable for children aged 3 and up. Wheelchair accessible for the first section. Extreme tour requires good fitness and is not suitable for young children.
Víðgelmir Lava Cave (West Iceland)
Iceland's largest lava cave at over 1,585 metres long, Víðgelmir is a spectacular underground landscape of lava formations, ice sculptures and colourful mineral deposits. The cave formed during an eruption roughly 1,100 years ago and features in several Icelandic sagas, including as a hiding place for outlaws.
A wooden walkway with lighting guides you through the cave, and knowledgeable guides explain the geological processes that created each formation. The coloured mineral deposits on the walls, reds, yellows and greens from iron, sulphur and copper, are particularly striking.
Access: Located near Húsafell in West Iceland, about 2 hours from Reykjavík. Makes an excellent stop on a Snæfellsnes Peninsula or Borgarfjörður day trip.
Cost: Around 6,500 ISK per person. Children under 5 are free.
Difficulty: Easy. The walkway is well maintained. Suitable for most ages and fitness levels.
Vatnshellir Cave (Snæfellsnes Peninsula)
An 8,000-year-old lava tube beneath the Snæfellsjökull glacier, Vatnshellir takes you down a spiral staircase into two levels of underground chambers. The deeper level sits 35 metres below the surface, and when the guide turns off all the lights, the absolute darkness is an experience in itself.
Jules Verne chose Snæfellsjökull as the entrance to the centre of the Earth in his 1864 novel, and standing in the dark silence of Vatnshellir, it is easy to understand why. The cave has a quiet, almost sacred atmosphere.
Access: Located within Snæfellsjökull National Park. Tours run regularly during summer and on a reduced schedule in winter.
Cost: Around 3,750 ISK per person. One of the most affordable cave experiences in Iceland.
Difficulty: Easy. The staircase is sturdy and the cave floor is level. Suitable for children aged 3 and up.
Lofthellir (Northeast Iceland)
Lofthellir is a hidden gem that most tourists never hear about. Located near Mývatn in northeast Iceland, this 3,500-year-old lava cave contains extraordinary natural ice sculptures that have formed over centuries from dripping water freezing inside the cave. Some of the ice formations are over a metre tall and look like they were carved by an artist.
Getting to the sculptures requires crawling through narrow passages and climbing over lava rocks, making this a genuine adventure rather than a walkway tour. It is not for the claustrophobic, but for everyone else, it is unforgettable.
Access: Guided tours only, departing from Mývatn. The cave entrance involves a short hike and then some hands-and-knees scrambling.
Cost: Around 8,500 ISK per person.
Difficulty: Moderate to challenging. You will crawl through tight spaces. Not suitable for young children or those with mobility issues. Minimum age typically 12.
Grjótagjá (Near Mývatn)
You might recognise Grjótagjá from Game of Thrones. This small lava cave near Lake Mývatn contains a geothermal hot spring with startlingly blue water. It is one of the most photographed caves in Iceland.
However, an important note: swimming in Grjótagjá is not permitted. The water temperature has been unstable since volcanic activity in the 1970s and 1980s, sometimes exceeding 50 degrees. The site is also culturally protected. You can walk up to the cave opening, peer inside and take photos, but the pool is off limits.
It is still worth a quick stop for the atmosphere and the photos, especially if you are already exploring the Mývatn area.
Access: Free. Short walk from a small car park off Route 860.
Difficulty: Easy. A 2-minute walk from the car park.
When to Visit Iceland's Caves
Ice caves (November to March): This is non-negotiable. Glacial ice caves are only safe when temperatures are consistently below freezing. The prime months are December and January, when the ice is at its most stable and the blue colours are most intense. February and March can also be excellent, with longer daylight hours making the approach hike more pleasant.
Lava tubes (year-round): Raufarhólshellir, Víðgelmir, Vatnshellir and Lofthellir are all accessible throughout the year. Summer offers the convenience of long days and warm weather for the approach, while winter visits mean you might have the cave almost to yourself.
The sweet spot: If you want both ice caves and lava tubes, visit in late November or early March. You get ice cave access and enough daylight to enjoy the lava tube tours comfortably.
Safety and What to Bring
Every reputable cave tour in Iceland provides helmets, headlamps and crampons (for ice caves). You do not need to bring caving equipment. However, you should:
- Wear warm layers. Caves maintain a constant temperature of around 0 to 4 degrees year-round. Even in summer, you will be cold without a fleece and waterproof jacket.
- Wear sturdy footwear. Hiking boots with ankle support are essential. Cave floors are uneven, wet and sometimes icy.
- Bring gloves. Touching cave walls for balance means your hands get cold fast.
- Carry a fully charged phone but know that there is no signal underground. Your phone is useful for photos, not for emergencies.
- Never enter a cave without a guide. Even caves that appear stable can have hidden hazards: loose rock, sudden drops, unstable ice, poisonous gases near geothermal areas. Guided tours exist for very good reasons.
Booking Tips
Ice cave tours in Vatnajökull sell out weeks in advance during peak season (December to February). If your heart is set on an ice cave, book as early as possible. Lava tube tours are easier to book on shorter notice, but summer weekends at Raufarhólshellir can get busy.
Most tours include transport from a nearby meeting point, but not hotel pickup in Reykjavík (unless specifically stated). Check your tour details carefully and factor in driving time.
If weather forces a cancellation, reputable operators will offer a full refund or reschedule. This is more common with ice cave tours, where conditions on the glacier can change rapidly. Do not be disappointed if this happens. It means the operator is prioritising your safety, which is exactly what you want.
Caves and the Icelandic Imagination
Caves hold a special place in Icelandic culture. The sagas mention outlaws living in caves for years. Folklore is full of stories about hidden people (huldúfólk) and trolls making their homes underground. Even today, Icelanders have a deep respect for the underground world, and many guides will share local legends alongside the geological explanations.
When you step into an Icelandic cave, you are not just seeing an interesting rock formation. You are entering a landscape that has shaped stories, sheltered outlaws and inspired one of the world's most enduring literary traditions for over a thousand years. That context makes the experience far richer than any photo can capture.