Quick summary
- This is not a normal hike. You cross a lava field, walk to the crater, then take a lift down into an empty magma chamber. The tour booked from this site is the Reykjavik: Thrihnukagigur Volcano Guided Hiking Day Trip.
- The path to the crater is about 3 km (2 miles) each way and usually takes about 45 minutes with your guide.[1] It is a relatively easy walk, but the lava terrain asks for sturdy shoes.
- The descent is 120 meters (400 feet), and the lift ride takes about 6 minutes.[2] Once down, you can spend around 30 minutes on the chamber floor before heading back up.[3]
- The Inside the Volcano tour operates from May 5th to October 30th every year.[1] This is a summer and early autumn adventure rather than a year-round outing.
- The booked tour is from US$432, lasts 4 to 6 hours, and offers pickup from Reykjavik.[4] You can cancel up to 24 hours in advance for a full refund.[4]
- Top choice Thrihnukagigur Hike from US$432 Duration4 - 6 hours[4]GuideLive guide, English and Icelandic[4]PickupPickup available[4]CancellationFree up to 24 hours[4] Check availability
- Raufarhólshellir by Bus from US$153 Duration3 hours[5]GuideLive guide, English[5]PickupPickup available[5]CancellationFree up to 24 hours[5] See this tour
- Reykjanes Hiking Tour from US$132 Duration9 hours[6]GuideLive guide, English[6]PickupPickup available[6]CancellationFree up to 24 hours[6] See this tour
It is believed that a deep underground rift drained the molten rock, leaving behind an enormous subterranean cavity spanning 3,270 square meters (35,200 square feet) with a depth of around 120 meters (394 feet).
A hike that ends inside the volcano
Before setting off
- Check your pickup point in Reykjavik and arrive at the meeting time.
- The tour uses a coach from the pickup area to the Bláfjöll meeting point.
- Pack layers, a waterproof jacket, and sun protection if the sky is clear.
- It can be cool inside the volcano, so bring a warm mid-layer.
A volcano you can walk into
Thrihnukagigur is not the volcano you expect. It sits quietly in the Icelandic highlands, its last eruption happening about 4,500 years ago.[7] Beneath the crater, the magma chamber is empty. The molten rock drained away through a deep underground rift, leaving behind a hollow cavity.[8] That emptiness is what makes this place so special: you can actually go down inside the volcano. The silence begins above ground, where the lava field stretches in every direction and the only sounds are wind and footsteps. By the time you stand at the crater, you have already travelled back to a moment in Iceland's deep past.
The story of how it became accessible is surprisingly recent. It was discovered in 1974 by cave explorer Árni B. Stefánsson and opened for tourism in 2012.[9] In the years since, a guided tour has become the practical way to see it. The Thrihnukagigur hike starts above ground, crosses a dark lava field, and ends with a descent into a colourful, cathedral-like space. The contrast between the grey rock outside and the red, yellow, and green walls inside stays with visitors long after they leave. For many, the strangest part is knowing that this vast room was once filled with liquid rock, and that time and geology opened it up.
What the Thrihnukagigur hike includes
The tour booked from this site is the Reykjavik: Thrihnukagigur Volcano Guided Hiking Day Trip. It starts with pickup in Reykjavik, carries you by coach toward the mountain, and includes the hike, the descent, and time in the chamber. The full experience lasts 4 to 6 hours.[4] The price is from US$432, and a live guide speaks English and Icelandic.[4] With transport, walking, and the lift combined in one trip, having one organiser handle the logistics makes the day feel smooth. You do not need to sort out a rental car or worry about finding a remote trailhead.
You can reserve now and pay later, and you can cancel up to 24 hours in advance for a full refund.[4] Pickup is available from Reykjavik.[4] That gives you flexibility if plans shift, which is useful in Iceland where weather can change the mood of a day. The tour is a manageable outing rather than a full marathon, so you may still have energy for an evening in the city afterwards. You will spend time outdoors and time underground, and both parts feel connected by the same landscape.
Guides and hikers gather near the crater before the descent begins.
The walk across the lava field
The Thrihnukagigur hike is an essential part of the experience. The path to the crater is about 3 km (2 miles) each way and usually takes about 45 minutes.[1] It is not a steep technical climb, but the ground is lumpy lava, and you need shoes with decent grip. The landscape around you is raw: mossy rock, volcanic cones, and wide views toward the coast. You walk at a relaxed pace, stopping to take in the surroundings, and the movement of the group keeps the energy light. There is no need to hurry, because the destination will still be there when you arrive.
There is no way to visit the volcano independently. The guided hike and a helicopter tour are the only ways to reach the base.[1] If you want to skip the walking, there is a helicopter option that flies you straight there.[10] For many people, the walk is part of the magic. It gives you time to feel the scale of the lava field before you disappear below it. The wind, the silence, and the crunch of volcanic rock underfoot all build the sense of moving toward something unusual. Each step makes the final descent feel more earned.
Going down into the magma chamber
When you reach the crater, the tour turns vertical. The descent into Thrihnukagigur is 120 meters (400 feet), and the lift ride takes about 6 minutes.[2] It is not a swift elevator drop; it is a slow, slightly surreal journey down into the mountain. After you arrive, you can spend around 30 minutes on the ground floor of the vault, exploring at your own pace.[3] The guide stays nearby, but you are free to wander and look. Looking up, you can see the opening far above, and the perspective makes the chamber feel even larger.
The chamber is enormous, with a bottom measuring 50 by 70 meters.[7] The walls glow with colours left behind by mineral deposits from the last eruption.[11] Red, yellow, green, and black streak the rock in ways that feel almost painted. The silence and the scale are hard to describe until you are standing there. You may find yourself speaking more quietly, simply because the space feels so vast and old. It is a strange, wonderful sensation to be indoors and outdoors at the same time, sheltered by rock yet surrounded by open air.
from US$432
The Reykjavik Thrihnukagigur Volcano Guided Hiking Day Trip starts from US$432[4] and lasts 4 to 6 hours.[4]
Practical planning for your visit
The season for the Inside the Volcano tour runs every year from May 5th to October 30th.[1] The minimum age is 8 years old.[3] If you are travelling with children, the age limit means families can plan around it. The path is not extreme, but it is uneven, so younger legs need some stamina and sturdy shoes. It is worth keeping the whole day flexible, because the weather in Iceland can change quickly and a little patience goes a long way.
The meeting point is at a ski cabin in Bláfjöll, the Blue Mountains, about a 30-minute drive from Reykjavík on paved road.[12] After that, the lava field walk begins. Wear layers, sturdy shoes, and a waterproof shell. Icelandic weather can shift quickly, and the ground can be wet even when the sky looks clear. A small backpack with water and snacks helps, though the tour itself is well organised and you will not need specialist gear. The walk is straightforward, but comfort makes all the difference.
Other volcano and lava experiences from Reykjavik
If you want more underground Iceland, Raufarhólshellir is a long lava tunnel formed about 5,200 years ago during the Leitahraun eruption.[13] It is a very different experience from Thrihnukagigur: you walk through a tube rather than descend into a chamber. The tunnel extends for 1,360 meters in total, with the main tunnel about 900 meters long.[13] A basic Raufarhólshellir lava tunnel tour from Reykjavik starts at US$68.[14] If you prefer to stay closer to the city, there are indoor and surface experiences too.
There are also surface volcano hikes around Reykjanes. A guided hike of Fagradalsfjall with a geologist starts at US$160.[15] If you want something shorter, the Lava Show in Reykjavik offers an immersive, indoor experience from US$53.[16] The Thrihnukagigur hike stands apart from all of these because you end up inside the mountain rather than on top of it or beside it. Those alternatives give you more ways to explore Iceland's volcanic personality, but none of them replace the feeling of standing on the chamber floor. The choice comes down to whether you want to go deep, go high, or stay above ground.
Why this tour deserves a spot on your list
The Thrihnukagigur hike is not just a walk; it is a journey through time. You stand on lava that erupted thousands of years ago, follow a trail toward a crater, and then enter a space that was once filled with liquid rock. The fact that you can do it safely, with guides, and still feel genuine awe is rare. The volcano keeps its colours, its silence, and its strange beauty waiting below the surface. It rewards curiosity, and it leaves you with a memory that feels almost impossible.
Plan for a half-day, book ahead, and bring a sense of curiosity. The operating season runs from May 5th to October 30th, so your travel dates need to line up.[1] The tour price is from US$432, and free cancellation up to 24 hours in advance gives you some breathing room.[4] For many travellers, the memory of standing inside that chamber becomes the highlight of their whole Iceland trip. It is a day to tell stories about for years, not just a checklist stop.
Size of the Thrihnukagigur chamber
Values from[7].
Volcano tour prices from Reykjavik
From-prices in US dollars from[4],[5],[15], and[16].
When to book your Thrihnukagigur day
Day trip in five steps
Meet in Reykjavik
Pickup is available from Reykjavik for the Thrihnukagigur hike. Be ready at your agreed pickup point before the coach leaves.
Ride to Bláfjöll
The meeting point is a ski cabin in Bláfjöll, about a 30-minute drive from Reykjavík on paved road.[12]
Hike to the crater
Follow your guide across the lava field for about 3 km each way, usually taking around 45 minutes.[1]
Descend into the chamber
Take the lift down 120 meters into the volcano[2] and spend around 30 minutes exploring the chamber floor.[3]
Return the same way
Ride the lift back up, hike to the coach, and enjoy the return journey to Reykjavik.
Ready to hike into Iceland's most curious volcano?
from US$432Reserve now & pay later
