Raufarhólshellir is one of Iceland’s longest and most accessible lava tunnels, located about 30 km southeast of Reykjavík and formed during a volcanic eruption roughly 5,200 years ago. The tunnel stretches for about 1.4 km and features vast chambers, colorful lava formations, and natural skylights where parts of the ceiling have collapsed and daylight enters the cave. Inside, visitors can see lava stalactites, flow patterns in the rock, and striking ice formations during winter months. Today the cave can be explored on guided tours along a marked path that allows visitors to safely experience the interior of an ancient lava flow.

QUICK NOTES:

• What it is: A tour around one of Iceland’s longest lava tunnels, created when flowing lava cooled on the surface while molten lava drained beneath it, leaving a hollow cave about 1.4 km long.

• Best season: The cave can be visited year-round, but winter often features beautiful ice formations inside the tunnel.

• Best time of day: The tours run daily from 09:00 - 17:00.

• Nice to know: Parts of the tunnel ceiling have collapsed over time, creating large skylights that bring natural light into the cave during sunlight hours and reveal the lava field above.