Iceland Víðgelmir Lava Cave

May 21, 2025

I took advantage of a rare 48 hour layover in Iceland to visit as many spots as possible. My husband and I spent the prior day touring the Golden Circle. Today, we ventured further afield to explore a massive Lava Cave. After this, we’d hike up some ancient volcanic craters.

I created a short video of the lava tube cave highlights.

Víðgelmir Lava Cave

I never thought I was that intrigued by caves, but I have yet to pass one up. While we have very few caves in Western Canada, there’s no shortage of them around the world. Iceland is no exception.

Most caves are deconstructed. This means they were solid rock at one point, but were carved out by flowing water. The Icelandic Víðgelmir cave is the opposite – it is a constructed cave. This means the cave was created. During a major volcanic eruption around 900 AD, the lava flowed down the valley, filling it up. As the outside of the flow cooled and hardened, the inside was well insulated and kept the lava flowing downhill. Over time, the lava flowed over top of the lava tube, creating layers that we saw near the cave entrance.

This is one of the Iceland’s largest and best preserved caves. This is because it filled with ice, and blocked the only entrance for a few decades. While other caves were ‘looted’, this one remained inaccessible and thus, fairly pristine inside.

The Cave Tour

To visit the cave, you must go with https://thecave.is/. Some people booked ahead, but we just arrived as it wasn’t high season. We were provided with a knowledgeable guide, a climbing helmet, and a head lamp.

This is a big new facility. There are several washrooms, and a large seating area. We ate our lunch before the tour, taking in the views from the floor to ceiling windows.

Our tour was about 16 people plus the guide. We were never rushed, and I felt that everyone had a great view. The tour was 1.5 hours long. I loved every minute of it, and I learned so much.

Clothing

As a Canadian, I can handle the cold. However, this cave tour is more standing than walking. The tour is 1.5 hours long, but we traveled less than 1 km underground. While I was completely fascinated the whole time, I definitely got cold. I brought extra clothes, and found myself slowing adding layers as we went. I also wore a toque, headband, and mittens.

The roof of the cave drips water. I recommend a water resistant jacket, preferably with a hood to avoid drips down your back.

The Lava Cave

We walked about 750 meters to the cave entrance, learning about the lava field as we went. 900 or so years is not very long in terms of lava, so there is very little regrowth. However, the sides of the original valley are lush, hinting at how much lava flowed into and covered the valley.

The cave entrance shows the layers of cooled lava that flowed over the field. The majority of the cave has a raised boardwalk. This means you cannot drop anything, because it will slip between the wooden boards and be lost forever. We did walk on the cave floor to get through ‘the squeeze,’ which I thought was very fun.

I was happy for my trail running shoes, which have more grip than the average running shoe. There were a few people having to walk very slow and carefully. There is also water on the cave floor, but we had no trouble keeping our feet dry.

Trolls

You’d think these caves would be great places for humans to live. Actually, no. It is widely known that Trolls live in caves, so humans were not about to go find them. There were some people who would risk a troll though – outlaws, or people who were shunned from society. Ancient punishment for criminal deeds meant leaving the security of the tribe. This cave has evidence of someone living in it for a while. Several hundred years ago, this cave would have been a lot warmer than it is now, making it quite cozy.

What about the trolls? Maybe they are still there.

This is just scratching the surface of the amazing sights and what we learned from the cave tour. I highly recommend this tour. Be sure to book ahead during the high season.

Next Up

After this, we wanted to stretch our legs and enjoy the sun with a hike. We visited ancient craters, and found a bonus – century old stone sheep corrals.

Here’s all the places we’ve visited in our whirlwind 48 hours in Iceland.

• Reykjavik
• Golden Circle Route
  • Þingvellir National Park
  • Bruarfoss Waterfall
  • Geysir – active geothermal geyser fields
  • Bruarhlod Canyon – giants anyone?
• Víðgelmir Lava Cave – impressive lava tube
• Grábrók Crater – ancient craters and sheep pens

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Alisen