Quick summary
- Open from May 5th to October 30th each year, so book a date inside that window.[1]
- Walk about 3 km each way to the crater, usually taking around 45 minutes with the guide.[1]
- Ride a lift 120 meters into a drained magma chamber and spend about 35-45 minutes inside.[2][3]
- From US$432 with pickup options, live guiding, pay-later reservation and free 24-hour cancellation.[4]
- Minimum age is 8, and the only ways to reach the volcano are this hike or a helicopter tour.[1][3]
- Top choice Thrihnukagigur Guided Hike from US$432 Duration4 - 6 hours[4]Rating4.85 from 630 reviews[4]GuideEnglish and Icelandic[4]CancellationFree up to 24 hours[4] Check availability
- Raufarhólshellir Lava Tunnel from US$153 Duration3 hours[5]Rating4.59 from 850 reviews[5]GuideEnglish[5]CancellationFree up to 24 hours[5] See this tour
- Volcano Hike & Reykjanes from US$132 Duration9 hours[6]Rating4.65 from 1,154 reviews[6]GuideEnglish[6]CancellationFree up to 24 hours[6] See this tour
At the top of this cone is a funnel-shaped opening, about 4×4 m (12×12 ft) wide entrance of a huge 120 m (400 ft) deep, bottle-shaped volcanic vault. The bottom measures 50×70 m (160×220 ft).
Step inside the crater if you want Iceland's strangest day
Check before booking
- Check the season before choosing dates
- Reserve now and pay later on GetYourGuide
- Free cancellation window if plans change
- Minimum age applies to the tour
On the day
- Meet the coach or arrange pickup in Reykjavik
- Check in at the Blafjoll meeting point
- Dress in layers for mountain weather
- Allow a full morning or afternoon for the trip
Why Thrihnukagigur is Worth Planning Around
Thrihnukagigur is one of the strangest places you can visit in Iceland. Instead of looking at a volcano from a distance, you go inside a drained magma chamber. The volcano last erupted about 4,500 years ago.[7] Its emptiness has a geological explanation: a deep underground rift drained the molten rock after the last eruption, leaving behind a hollow cavity.[8]
The walls of the chamber are coloured by mineral deposits left by that last eruption, so the rock around you shifts in rusty reds, yellows, greens and greys.[9] The base cannot be visited independently; the only ways to get there are the guided tour hike or a helicopter tour.[1] A guided hiking day trip combines the walk across the lava field with the descent into the crater, and it is a genuinely unusual day out.
The Best Time to Visit Thrihnukagigur: May to October
The single most important thing to know is the operating season. Inside the Volcano tours run every year from May 5th to October 30th.[1] That means you cannot book this experience in the deep winter, no matter how much you want to. The practical approach is to choose a date inside that window and then build the rest of your Iceland itinerary around it.
Within the season, your choice depends on what you want. Midsummer brings the longest daylight and often the mildest conditions, while later in the season trails are usually quieter and the low sun brings out rich colours on the lava. The tour runs through the season, so the same route and the same lift are available from start to finish.[1] Because dates fill up, especially in summer, it is sensible to book as soon as your travel dates are firm.
To avoid the busiest weeks, choose dates soon after the season opens or just before it closes. You will still get the full experience, including the hike, the descent and time on the chamber floor. Just be ready for changeable weather in the highlands; a waterproof layer and sturdy shoes matter more than the month on the calendar.
The trail crosses the old lava field before the crater comes into view.
What the Hike to the Volcano Is Really Like
The day starts at a meeting point in Blafjoll, about a 30-minute drive from Reykjavik on paved road.[10] From there you walk with a guide across the old lava field. The path to the volcano is about 3 km (2 miles) each way and usually takes about 45 minutes.[1] It is relatively easy, but it is not a boardwalk; you are walking over uneven volcanic terrain, so good footwear makes a real difference.
Along the way you get wide views over the lava plain and the flat-topped ridges around it. The trail approaches the red scoria cone of Thrihnukagigur, and soon the funnel-shaped opening appears ahead. This is one of only two ways to reach the base of the volcano, so the hike is not just transport; it is the opening act of the experience.[1] Guides pace the group and there is no rush.
Do not skip the walk in favour of something faster unless you are genuinely unable to hike. The guide will point out lava formations and explain the landscape as you go. The reward for the 45-minute approach is the moment when the crater rim comes into view and you realise you are about to go underground.[1]
Going Down: The Descent and the Magma Chamber
At the crater, you step into a lift that lowers you into the volcano. The descent is 120 meters (400 feet) and the lift ride takes about 6 minutes.[2] The opening at the top is a funnel-shaped entrance to a huge bottle-shaped volcanic vault, and the bottom of that vault measures 50×70 m (160×220 ft).[7] It feels less like a cave and more like a cathedral made of rock.
Once you are on the chamber floor, you have time to look up, walk around, and take in the scale. Visitors spend approximately 35-45 minutes inside the volcano including the descent, time on the chamber floor, and the ascent.[3] That includes the return lift, so you have a solid stretch of time to explore. The colours are the thing people remember: bands of mineral-stained rock curve up the walls and disappear into the shadows.[9]
Why is it empty? Because a deep underground rift drained the molten rock after the volcano's last eruption, leaving behind a hollow cavity.[8] That is what makes this visit possible. You are standing in a space that was once filled with magma, and the stillness inside is like nothing else on a typical Iceland itinerary.
from US$432
From this price you get 4 to 6 hours, live guiding in English and Icelandic, pay-later booking and free 24-hour cancellation.[4]
How to Book the Thrihnukagigur Guided Hiking Day Trip
The tour to book from this site is the Reykjavik Thrihnukagigur Volcano Guided Hiking Day Trip. It is priced from US$432 and lasts 4 to 6 hours.[4] Pickup is available, the live tour guide speaks English and Icelandic, and you can cancel up to 24 hours in advance for a full refund.[4] The listing also lets you reserve now and pay later.[4]
The trip has a minimum age of 8 years old.[3] That matters if you are travelling with younger children, because they cannot join this particular tour even if they are happy walkers. The tour is guided in English and Icelandic, so if you are a native speaker of either language you will get the details directly.[4]
Pickup is available, and the listing offers a range of drop-off locations around Reykjavik.[4] Check availability when you book to see pickup choices and starting times. The listing shows a 4 to 6 hour duration, so treat it as a half-day or longer and plan the rest of your day around it.[4]
Other Lava Experiences to Compare
Thrihnukagigur is the headline act, but it is not the only way to explore Iceland's volcanic plumbing. If you want a shorter and cheaper underground fix, Raufarhólshellir lava tunnel can be visited from Reykjavik by bus from US$153, with the tour lasting about 3 hours.[5] The tunnel itself is 1360 m long and formed about 5200 years ago during the Leitahraun eruption.[11]
For a surface-level volcano experience, the Volcano Eruption Site and Reykjanes Hiking Tour starts from US$132 and runs for 9 hours, covering the Reykjanes peninsula.[6] You get a live English-speaking guide, pickup options, and free cancellation up to 24 hours in advance.[6] It is a different kind of day, less about going underground and more about seeing eruption landscapes, hot springs, and lava fields above ground.
If you are short on time or want a city-based primer, the LAVA SHOW in Reykjavik offers an immersive experience from US$53 and lasts 50 to 75 minutes.[12] It is not a hike, but it gives you the sensory version of molten rock without leaving the city. Use it as a warm-up before the real thing, or as a backup if the Thrihnukagigur season has already closed.
Practical Tips for Your Visit
Wear layered clothing and waterproof shoes. You will be outside for the hike across the lava field before you go underground, and the weather can change quickly in Iceland. The path is relatively easy, but it is 3 km each way over uneven ground, so trainers are not the best choice.[1] Bring a small daypack with water and a snack, and keep your phone charged for photos.
Arrive at the meeting point in Blafjoll with time to spare. The drive from Reykjavik takes about 30 minutes on paved road, and the hike starts at the crater after a guided approach.[10] The minimum age is 8, and you cannot drive to the crater and walk in on your own.[1][3]
Book early if you have a fixed date. The season runs from May 5th to October 30th, and popular summer slots go quickly.[1] Use the GetYourGuide listing to reserve now and pay later, and remember that you can cancel up to 24 hours in advance for a full refund if your plans change.[4]
Time spent on key parts of the Thrihnukagigur tour
Compare lava experiences by price
Booking window and timing
Plan your volcano visit
Check the season
Tours run from May 5th to October 30th every year, so pick a date inside that window first.[1]
Book your spot
The guided day trip is from US$432 with reserve now and pay later and free cancellation up to 24 hours in advance.[4]
Pick your pickup
Pickup is available, with a live guide in English and Icelandic; check availability for exact options.[4]
Get to Blafjoll
Plan a 30-minute paved road drive from Reykjavik to the meeting point at the ski cabin.[10]
Hike to the crater
Walk about 3 km each way, usually around 45 minutes, before you reach the opening.[1]
Descend and explore
Ride down 120 meters into the chamber and spend roughly 35-45 minutes inside.[2][3]
Ready to stand inside an empty volcano?
from US$432Reserve now & pay later
