Formed during an eruption 9,000 years ago, Gjabakkahellir lava tube cave in Thingvellir has a unique feature in that it’s open on both ends so visitors are able to walk directly through it. Inside are incredible rock formations in various colors, and stalactites of all shapes and sizes.

Gjabakkahellir cave is a 360 meter long lava tube located in the National Park Thingvellir and was discovered in 1907 when workers were preparing a road between Thingvellir and Geysir for the King of Denmark, which at that time ruled Iceland as a colony.

Spelunking in Gjabakkahellir cave

Gjabakkahellir is easily accessible as there is only a 50 meter walk from the road to the opening of the cave. Once inside it has all the typical features of a lava tube, the lava falls and shark tooth stalactites being particularly impressive.

The cave floor is covered with large rocks that have fallen from the cave ceiling in the cooling phase of lava field and participants will in places have to use both hands and feet to navigate through the rough terrain.

Since then more than a dozen of caves have been discovered in the area and one of those appears just as a hole into the ground within a 20 meter distance from Gjabakkahellir.