Head into the Leitahraun lava field for a small-group, geologist-led trip through Arnarker — a 516 m lava tunnel near Reykjavik. Expect basalt chambers, winter ice formations, and hands-on lessons about Icelandic volcanism.
More ways to explore the area's outdoor wonders
You step from the van into a broad, wind-cut plain and the ground seems older than the sky — black pahoehoe and jagged ʻaʻā stretching toward low ridges where smoke once rose. The Arnarker lava tunnel waits, its mouth a simple notch in the Leitahraun field; inside, rock curves into passages that remember fire.
Difficulty
moderate
Duration
5 hours
Fitness Level
Moderate — able to walk over uneven rocky ground for several hours and manage brief low crawls.
Wildlife
History
Leitahraun formed about 5,200 years ago as part of the Brennisteinsfjöll volcanic activity; human use of the area has shifted from pastoral routes to modern geological tourism.
Conservation
Stick to marked approaches and avoid moving fragile ice or rock features; the volcanic surface is slow to regenerate and trampling damages lichens and microhabitats.
Reserve your spot on the Geological Lava Tunnel Adventure in Arnarker Cave today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Wear grippy boots
The cave floor is uneven and can be slippery; ankle-supporting, lug-soled boots reduce the risk of twists and falls.
Layer for cold and wet
Temperatures inside stay near freezing in winter and cool year-round; a waterproof outer shell and warm midlayer are sensible.
Bring a small dry pack
Keep phone, ID, and medications dry and accessible — pockets can fill with water or mud in low areas.
Go early or late to avoid crowds
Small-group tours are limited to six, but choosing off-peak tour times yields quieter photography and more time for questions.
Sturdy hiking boots
Provide traction and ankle support on uneven basalt and icy patches.
Insulating midlayer (fleece or synthetic)
Keeps core warm in the cave’s cool, stable temperatures.
Waterproof outer shell
Protects against meltwater and wind-chill at the cave entrance and during approach.
winter
Spare headlamp or small torch
Guides provide lamps, but a backup ensures you won’t be left in the dark if batteries fail.