Thríhnúkagígur Volcano

About Thríhnúkagígur Volcano

Þríhnúkagígur (Thríhnúkagígur) is a dormant volcano in the Bláfjöll country park, about 30 minutes' drive south-east of Reykjavík. Its name means crater of the three peaks. It last erupted more than 4,000 years ago, and after the eruption the magma drained away from the conduit instead of solidifying, leaving an open, bottle-shaped chamber beneath a small opening in the crater. It is the only place where visitors can be lowered into a volcanic magma chamber of this kind.

Access is only on the guided Inside the Volcano tour. The day starts with a guided hike of about 3.2 km each way across moss-covered lava from the car park to a base camp beside the crater. From there, small groups wearing helmets and harnesses are lowered around 120 metres in an open cable lift to the floor of the chamber. You then have roughly 30 to 45 minutes to walk around with a guide and look at the walls, which are streaked red, yellow and black by minerals and oxidation. Back at base camp, lamb soup, with vegetarian options, and hot drinks are served.

The tour runs only in the snow-free season, roughly from mid-May to late October, and has limited places, so book ahead. It is one of the more expensive tours in Iceland; check the operator for current prices. There is a child rate for ages 8 to 12, and participants need to be fit enough for the hike, which takes around 45 minutes each way on uneven ground. You can drive yourself to the meeting point in Bláfjöll or book a pick-up from Reykjavík.

Wear hiking boots, warm layers and waterproofs; it is cool inside the chamber and the weather on the lava can change quickly. The tour pairs well with other volcanic sights near the capital, such as the Raufarhólshellir lava tube, the Geothermal Exhibition at Hellisheiði power plant, and the lava fields at Fagradalsfjall on the Reykjanes peninsula.