Thrihnukagigur - Three Peaks Crater

Useful Information

Location: South of Reykjavik.
Open: 10-MAY to OCT daily 8-.
Tours as needed.
Fee: Adults ISK 44,000, Children (8-12) ISK 22,000, Children (0-11) not allowed.
Classification: SpeleologyKarst Cave
Light: LightIncandescent Electric Light System
Dimension: VR=200 m, T=3 °C.
Shaft: D=4 m.
Magma chamber: VR=120 m, L=70 m, W=50 m.
Guided tours:
Photography: allowed
Accessibility: no
Address: Thrihnukagigur, Inside the Volcano tour, 3H Travel, Tel: +354-519-5609. E-mail:
Tickets: Tel: +354-760-1000.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


2010 elevator installed for use by researchers.
1974 discovered by cave explorer Árni B. Stefánsson.
2012 opened to the public.
AUG-2015 Icelandic band Kaleo shot their music video for the song Down we go in the cave.
18-JUN-2016 the world's first public performance inside the dormant magma chamber of a formerly-active volcano.


Þríhnúkagígur (Thrihnukagigur - Three Peaks Crater) is a small hill located south of Reykjavik in the Bláfjöll mountain range. It is a volcanic cinder cone with a crater on top, but it is quite special, and I am not talking about the three peaks. In the middle of the crater is a pothole leading to the empty magma chamber of the dormant volcano. The last eruption was 4,000 years ago and created a huge dome shaped cavern, the empty space where the magma had been before. This happens quite often, actually, but in most cases the chamber is too big and collapses forming a caldera. Or it does not collapse but is not accessible from the surface because the vent is filled with the last sputters of magma, which did not reach the surface because the the eruption stopped.

The chamber was discovered by the cave explorer Árni B. Stefánsson in 1974, and since then he was aware that this place is really special. He had the idea that it should be opened to the public for this reason, but was not able to get it financed. Until finally in 2012 an elevator was constructed to bring people into the cave. Since then the cave is open to the public during summer.

The elevator is not like an elevator in a building, there is no closed cabin. Its more like those working platforms used by window cleaners at skyscrapers. A metal board is the floor, metal tubes form a railing on four sides, and in each corner is a steel cable where the platform is fixed. There is a metal bridge across the opening and the open cable lift is lowered from this bridge. The vent is quite narrow and so there are small wheels at the sides which roll down the shaft wall and prevent that the elevator entangles with the wall. Once in the huge dome like chamber it goes down slowly to the floor.

The inside of the chamber was very carefully developed with indirect electric light. There are some trails to allow the visitors to walk around, but they are just like walking trails in the mountains, not paved like in a show cave. And anything which is brought in, is taken out again later. The cave is illuminated by powerful floodlights mounted at the elevator. The whole system is more or less provisional, but the special feature is that it can be dismantled at any time with minimal traces. An elegant solution, and obviously cost effective. The parts are brought in by helicopter each May, with three helicopters this takes more than a week. In November the whole structure is dismantled and nothing is left behind. Nevertheless there is an ongoing discussion if the elevator should be replaced by an artificial tunnel.

The place is so exceptional, it was soon discovered by location hunters, and it has been used for various purposes. The Icelandic band Kaleo shot their music video for the song Down we go in the cave in 2015. In 2016 it was the place of the world's first public performance inside the dormant magma chamber of a formerly-active volcano. During the Secret Solstice music festival a sort of "cozy" music event with only 20 guests was organized. The band and the guests were flown in by helicopter. It was quite a success, but the tickets were pretty expensive. And sold out.

Regular tourists reach the place on foot, the hike from the parking lot takes an hour, 3,5 km across the breathtaking landscape of a lava stream. The basaltic rock on the surface is sharp edged, so its essential to wear very sturdy boots. At the cabin the visitors are equipped with harnesses and helmets. The lift operator attaches each visitor's harness to the elevator frame with carabiners for security reasons. Then the elevator goes down 120 m to the floor which takes 6 minutes. Groups are split into smaller groups of six to seven, for the elevator. If you go in with the first you will also go out with the first, so every participant has the same time uinderground.

The tours are quite expensive and take five to six hours, which includes anything from the pickup at your hotel in Reykjavík. Its half an hour drive, one hour walk, one hour in the cave, one hour walking back and then the drive back, plus some time for picking up and dropping off at different hotels. Fortunately a traditional Icelandic meat soup or vegetable soup and hot coffee, tea, or chocolate are served after the cave tour. We would recommend to drive yourself, so you can see other things before or after your cave tour.