Exploring Lava Tubes in Iceland

Knowing Your Limits: I Quit, and That's Okay
The Absolute Best Citizen Science Adventures

The darkness was absolute.

I squinted, trying to find some hint of light, something to ease the small, instinctual thrill of terror that comes along with abrupt, total blindness.

I knew I was safe, yet I reached over, finding Tara’s hand, squeezing it for reassurance.

Deprived of sight, other senses opened up to me. I could smell the cool, damp walls around me. I could feel the ridges and bumps of the basalt ledge that I was sitting on. And I could hear. All around me, dripping water created a subterranean symphony as ice flows gave way to the promise of spring warmth above.

“Our legends are newer than most.”

The sound of our guide’s voice jolted me out of my reverie. He was to my right, several feet away. He was speaking quietly, but in this darkness his words may as well have been a shout.

He explained to us the mythical origins of these lava tubes, formed thousands of years ago by vitrified magma and basalt.

According to Norse legend, it was one of these tubes where Loki, the mischievous trickster, met a grizzly fate. As punishment for arranging the death of the much-favored god Baldr, Loki is condemned to the caves, bound by the entrails of his own son.

Guarded by the goddess Skaði, a serpent is held over his eyes, dripping venom into them for eternity. Loki’s wife, desperate to ease his pain, holds a bowl that collects the venom. Whenever the bowl fills, though, she must turn away and empty it, and the venom splashes the trickster, making him bellow in pain and causing the earthquakes that are so common in Iceland.

As the story reached its conclusion, we all sat in silence, listening to the dripping of the cave. It was not the first legend we had heard since arriving in Iceland, pulled from the Old Norse Edda, but it rang in my ears, more powerful than the others. More memorable for the fact that I heard it deep within the bowels of the story’s setting.

Our guide flicked on a lighter, and the sudden intrusion was blinding. I blinked, my eyes adjusting slowly. Then, one by one, we turned our headlamps back on, refamiliarizing ourselves with the world of sight.

Exploring lava tubes in Iceland

An intimate caving experience

I’ll be the first to admit that often times your typical walking cave tour can become a bit monotonous. You can only have features like “cave bacon” or the differences between stalactites and stalagmites explained to you so many times before beginning to wonder if every cave is completely identical.

Two years ago, I had my first chance to deviate from the caving norm for tourists. Together with Tara and Marie from Ardent Camper, we went on a spelunking tour of Longhorn Cavern in Central Texas.

It was an amazing experience, and I was immediately enamored by the more adventurous side of caving. So when DIVE.IS offered to extend our snorkeling tour of Silfra into a two-part experience that included exploring lava tubes, we immediately agreed. That definitely sounded like a deviation from the norm.

All geared up and ready to go!


When we first arrived at the site where we would be caving, there was nothing to indicate that we were about to make our way beneath the surface. We were surrounded by a seemingly unbroken field of white snow.

Doesn't exactly look like cave country, does it?
Doesn’t exactly look like cave country, does it?

We were supplied with crampons and helmets, complete with headlamps — my first indication that the trip would not be a simple walking tour. We also had the option of wearing waterproof overalls, which we passed on.

The entrance to the lava tubes emerged from the snow, a literal hole in the ground. To enter, we had to lie down on our backs, scooting in feet first while we propelled ourselves with our hands on the rock overhead.

Tara takes one final look at the outside world.
Tara takes one final look at the outside world.

It was a tight squeeze, but once inside the cave opened up significantly, and we could stand without issue. Everything glittered as our headlamps bounced off inches-thick layers of ice, covering the basalt rock near the entrance. It was a subterranean winter wonderland.

The unique geology of lava tubes

The caves you are probably most familiar with are those created by erosion. These water-formed caves are carved out over thousands and thousands of years, succumbing to the relentless force of underground rivers.

Lava tubes, however, are only as old as the most recent volcanic eruption. They are formed not by water, but by magma. When the magma of an eruption begins to cool sometimes the outer edges will cool first, and movement slows. The hotter, still liquid magma flows through the cooler portion, creating a straw effect. Eventually, the liquid magma empties out entirely, leaving only the hollow tube behind.

The lava tubes we found ourselves walking through were infants on a geological scale — a mere 2,000 years old.

Within the cave it is easy to see the flow of magma as it made its way through the tube. It’s even possible to see where lava once dripped from the ceiling, and to estimate how fast the magma may have been moving.

Can you imagine hot lava dripping down from this ceiling?

Emerging into sunlight

With our small group of five people plus our guide, we crawled and squeezed and climbed through crevices, over fallen boulders, and down tunnels. For the length of our tour we were whisked into a place that was truly other-worldly, and our guide was quick to share the cave’s geology as well as the local lore.

Pulling ourselves upwards by a rope, we emerged back into the world of the sun, blinking against the blinding snow. In our journey we had made a giant ‘U’ shape, almost completing the oval to end within a few steps of where we started. All I could see from this angle were rock piles and snowdrifts, and it was a bit jarring to think that I had been beneath all of that, just moments before.


Exploring lava tubes in Iceland is something that I would absolutely recommend — especially to the naysayers who think that all caving experiences are the same! It was truly a unique opportunity, and it provided us with the chance to learn about the geology and mythology of Iceland in a unique setting that made it truly memorable.

Outbound Adventurer is grateful to DIVE.IS and Iceland Expeditions for providing us with the opportunity to review their tour. As always, our opinions are completely honest and our own. If you are interested in booking a snorkeling or scuba diving tour, here is the relevant contact information:

Website: www.dive.is or www.icelandexpeditions.is
E-mail: dive@dive.is or info@icelandexpeditions.is
Phone: 00354 578 6200 0r 00354 777 0708

Knowing Your Limits: I Quit, and That's Okay
The Absolute Best Citizen Science Adventures
  • This looks so much fun. I like the small group size too. We were in Iceland a few years ago and absolutely fell in love with the unique country. I wish we had more time to do activities like this. That ceiling photo is amazing!

    • Thanks for the comment! The lava tubes were really neat, but they’re not an Iceland exclusive! Most volcanic regions have them, so you might be able to squeeze them in on your upcoming travels!